1/2
Throughout this post, I'm going to horribly misuse, twist and reword HH's earlier statement which BV posted - and I am probably paraphrasing his words here - that Bauddha Dharma 'subverted the ancestral Dharma' (or something). He probably meant something deep with the original unadulterated statement, but I simply mean to use this handy phrase in the sense that Bauddha Dharma hijacked local indigenous religions - where it did not succeed in completely eradicating these religions - for legitimising Buddhism.
Something Hindus and other Indians eagerly forget is that Buddhism is a missionary religion and all that that implies and has meant. It didn't spread easy as melted butter over Asia.
First, Buddhism tried to persecute local religions to extinction - for example, even later, it consciously and systematically attempted this in Tibet and succeeded (a decent book on the subject is better, but www.buddhistchannel.tv/index.php?id=40,5769,0,0,1,0 hints at a little on the Bon case, even though it also brushes over the difficulties and the extent of what has been lost).
But elsewhere, after the initial attempts to suppress the local religions in its favour had failed (e.g. E Asia), Buddhism had to compromise into becoming Mahayana Buddhism forms in order to gain laity: subverting local religions by making the local Gods into "upholders of Bauddha Dharma" and by insinuating Buddhist identity and/or superiority into local religions' narratives concerning the native religion's Gods.
The only way Buddhism could get any hold on the local religion's laity is by having Gods. Buddhism acquired the necessary Gods from local religions. And frequently, Buddhism used Hindu religion (Gods and rituals) - both pre-existing established Hindu religion such as in Thailand, Cambodia, Siberia and E Asia, as well as elements of Hindu religion that Buddhism, when it later arrived, would import on top of that from India - to pave its path to smooth conversion. That's because these Asian populations were used to their own Gods, which made them open to Hindu Gods when Hindus went to SE and E Asia. From experience, Buddhism knew it spreads well atop a Hindu base and so automatically used it everywhere it succeeded.
This is quite in contrast to how Hindu religion had established itself in parts of Asia earlier, which was possible because Hindu Dharmic tradition could be incorporated easily into the local religion: Hindu Gods easily added to the local religion's pantheon (e.g. Shinto in Japan, also Tibet, Thailand - even some Hindu elements in Daoism), the way GrecoRoman Gods and hence even their associated tradition easily added to Middle-Eastern pantheons such as among Arabians. To this day, at least some full Shintos keep fully-Hindu Gods (i.e. not the Buddhist versions of Hindu Gods) alongside their own pantheon, even though they do not keep a Buddha or do anything Buddhist.
Hindu religion has lost much of Asia at the expense Buddhism: Buddhism took every part of Asia where Hindu religion had earlier been able to take root alongside local religions among the local population. Buddhism used Hindu Gods/religion to do so, just as Buddhism also used local Asian religions to achieve its conversions. Buddhism's success in southeastern and eastern Asia is entirely due to local religions and Hindu religion. E.g. Mahayana Buddhism in east Asia *is* largely hijacked Taoism and Shinto - and the local features of Buddhist culture there is actually Taoist and Shinto religio-culture (but today's Hindus still cheer Buddhism as "our greatest export"). Similarly, Buddhism in Tibet ended up importing Hindu elements (DMVs, associated rituals and related) from the NE of India, and once again masked the fundamentally Hindu identity of the Gods by giving them Buddhist identities.
There simply is no Mahayana Buddhism in the far east without their local (Taoist and Shinto) Gods. It is entirely due to the native religions of Taoism and Shinto that the character of Buddhism is the way it is in the far east. Even today, many among the lay Mahayana Buddhists of the far east worship mainly the Taoist Gods at home and in their ancestral temples. However, even if MB in China and Taiwan is permeated with Taoism, Taoism itself has sadly been deposed, replaced and marginalised. The understanding of its Gods has been subverted by forced association and assimilation with unrelated Buddhism. Hindus have been more fortunate than these others in that, unlike E Asia where the local religions used to be the vast majority once upon a time and was thereafter replaced by Buddhism, India is still majority Hindu, following the old religion of the Gods.
SE Asia was largely Hindu (Hindu Gods in their pantheon) before it ever became Buddhist. Thailand, Cambodia, parts of Hindu-then-Buddhist-then-islamist Indonesia, etc. The Gods in the Buddhism you see there is again from their previous religion: Hindu Dharma. In Sri Lanka, there are some 'Buddhist' laity whose primary worship is to Murugan/Kartikeya (frequently alongside his two consorts). Whether they do anything Buddhist or not I don't know. Obviously it is their ancestral Gods they continue to worship as per their ancestral religion, and in this way they remain attached to their old religion in all but identity-label. IIRC, SL's Theravada Buddhists reason their behaviour away with how such attachment to Gods will help with Buddhist meditation. (Even though the laity in question seem to regard these Gods as an end in themselves, rather than keeping nirvana firmly in mind.)
Before any declare that, on the strength of the above examples, it somehow magically 'proves' that "of course this means Buddhism (naturally) has Gods", they can point to a Buddhism with consistent Gods: one which has Gods in all places where Buddhism exists AND moreover has the same Gods. It does not. (Because it is not a Gods-based, Gods-centred religion.)
Where Buddhism exists AND has Gods, it has the (a) local, pre-Buddhist Gods of the region plus possibly (b.) either Hindu Gods from pre-Buddhist Hindu presence or from Hindu Gods imported by Buddhism to help with converting laity used to Gods.
Note that regardless of Buddhist superimpositions on top of Shinto and Taoist Gods etc as being "upholders of Bauddha Dharma", these Gods are NOT Buddhist and are unrelated to Buddhism (though they may be attached to any among Buddhist laity who continue to be devoted to them, for the sake of this devotion).
Indians tend to regard Buddhism as one of our best/greatest exports, but taking a step back, it wasn't great news all round. India - the originating locus of this missionising - is responsible for what was done to the native traditions of Tibet, Japan, China (and Korea too apparently) and large parts of SE Asia. The one 'upside' is that Hindus and Hindu Dharma are not at all responsible for any of it - since Hindus are not Buddhists.
Missionary religions are simply a nuisance. Further to the west, the GrecoRomans fortunately didn't take to Buddhism greatly (it was an alien religion in more ways than one) and stuck to their Gods like reliable, loyal, sensible people would. And so, one doesn't hear of Zeus and the other GR Gods being "bodhisattvas" - which of course they aren't and wouldn't ever be. The Persians more significantly commented on the push they felt from the east by Buddhism, round about the time when they found themselves beleaguered by christianism that emanated from the west. (I don't know their particular reasoning for feeling concerned by the onset of Buddhism, but it may have been incompatibility with their established religion, Mazda Yasna, and the fact that Buddhism was very missionary.)
Throughout this post, I'm going to horribly misuse, twist and reword HH's earlier statement which BV posted - and I am probably paraphrasing his words here - that Bauddha Dharma 'subverted the ancestral Dharma' (or something). He probably meant something deep with the original unadulterated statement, but I simply mean to use this handy phrase in the sense that Bauddha Dharma hijacked local indigenous religions - where it did not succeed in completely eradicating these religions - for legitimising Buddhism.
Something Hindus and other Indians eagerly forget is that Buddhism is a missionary religion and all that that implies and has meant. It didn't spread easy as melted butter over Asia.
First, Buddhism tried to persecute local religions to extinction - for example, even later, it consciously and systematically attempted this in Tibet and succeeded (a decent book on the subject is better, but www.buddhistchannel.tv/index.php?id=40,5769,0,0,1,0 hints at a little on the Bon case, even though it also brushes over the difficulties and the extent of what has been lost).
But elsewhere, after the initial attempts to suppress the local religions in its favour had failed (e.g. E Asia), Buddhism had to compromise into becoming Mahayana Buddhism forms in order to gain laity: subverting local religions by making the local Gods into "upholders of Bauddha Dharma" and by insinuating Buddhist identity and/or superiority into local religions' narratives concerning the native religion's Gods.
The only way Buddhism could get any hold on the local religion's laity is by having Gods. Buddhism acquired the necessary Gods from local religions. And frequently, Buddhism used Hindu religion (Gods and rituals) - both pre-existing established Hindu religion such as in Thailand, Cambodia, Siberia and E Asia, as well as elements of Hindu religion that Buddhism, when it later arrived, would import on top of that from India - to pave its path to smooth conversion. That's because these Asian populations were used to their own Gods, which made them open to Hindu Gods when Hindus went to SE and E Asia. From experience, Buddhism knew it spreads well atop a Hindu base and so automatically used it everywhere it succeeded.
This is quite in contrast to how Hindu religion had established itself in parts of Asia earlier, which was possible because Hindu Dharmic tradition could be incorporated easily into the local religion: Hindu Gods easily added to the local religion's pantheon (e.g. Shinto in Japan, also Tibet, Thailand - even some Hindu elements in Daoism), the way GrecoRoman Gods and hence even their associated tradition easily added to Middle-Eastern pantheons such as among Arabians. To this day, at least some full Shintos keep fully-Hindu Gods (i.e. not the Buddhist versions of Hindu Gods) alongside their own pantheon, even though they do not keep a Buddha or do anything Buddhist.
Hindu religion has lost much of Asia at the expense Buddhism: Buddhism took every part of Asia where Hindu religion had earlier been able to take root alongside local religions among the local population. Buddhism used Hindu Gods/religion to do so, just as Buddhism also used local Asian religions to achieve its conversions. Buddhism's success in southeastern and eastern Asia is entirely due to local religions and Hindu religion. E.g. Mahayana Buddhism in east Asia *is* largely hijacked Taoism and Shinto - and the local features of Buddhist culture there is actually Taoist and Shinto religio-culture (but today's Hindus still cheer Buddhism as "our greatest export"). Similarly, Buddhism in Tibet ended up importing Hindu elements (DMVs, associated rituals and related) from the NE of India, and once again masked the fundamentally Hindu identity of the Gods by giving them Buddhist identities.
There simply is no Mahayana Buddhism in the far east without their local (Taoist and Shinto) Gods. It is entirely due to the native religions of Taoism and Shinto that the character of Buddhism is the way it is in the far east. Even today, many among the lay Mahayana Buddhists of the far east worship mainly the Taoist Gods at home and in their ancestral temples. However, even if MB in China and Taiwan is permeated with Taoism, Taoism itself has sadly been deposed, replaced and marginalised. The understanding of its Gods has been subverted by forced association and assimilation with unrelated Buddhism. Hindus have been more fortunate than these others in that, unlike E Asia where the local religions used to be the vast majority once upon a time and was thereafter replaced by Buddhism, India is still majority Hindu, following the old religion of the Gods.
SE Asia was largely Hindu (Hindu Gods in their pantheon) before it ever became Buddhist. Thailand, Cambodia, parts of Hindu-then-Buddhist-then-islamist Indonesia, etc. The Gods in the Buddhism you see there is again from their previous religion: Hindu Dharma. In Sri Lanka, there are some 'Buddhist' laity whose primary worship is to Murugan/Kartikeya (frequently alongside his two consorts). Whether they do anything Buddhist or not I don't know. Obviously it is their ancestral Gods they continue to worship as per their ancestral religion, and in this way they remain attached to their old religion in all but identity-label. IIRC, SL's Theravada Buddhists reason their behaviour away with how such attachment to Gods will help with Buddhist meditation. (Even though the laity in question seem to regard these Gods as an end in themselves, rather than keeping nirvana firmly in mind.)
Before any declare that, on the strength of the above examples, it somehow magically 'proves' that "of course this means Buddhism (naturally) has Gods", they can point to a Buddhism with consistent Gods: one which has Gods in all places where Buddhism exists AND moreover has the same Gods. It does not. (Because it is not a Gods-based, Gods-centred religion.)
Where Buddhism exists AND has Gods, it has the (a) local, pre-Buddhist Gods of the region plus possibly (b.) either Hindu Gods from pre-Buddhist Hindu presence or from Hindu Gods imported by Buddhism to help with converting laity used to Gods.
Note that regardless of Buddhist superimpositions on top of Shinto and Taoist Gods etc as being "upholders of Bauddha Dharma", these Gods are NOT Buddhist and are unrelated to Buddhism (though they may be attached to any among Buddhist laity who continue to be devoted to them, for the sake of this devotion).
Indians tend to regard Buddhism as one of our best/greatest exports, but taking a step back, it wasn't great news all round. India - the originating locus of this missionising - is responsible for what was done to the native traditions of Tibet, Japan, China (and Korea too apparently) and large parts of SE Asia. The one 'upside' is that Hindus and Hindu Dharma are not at all responsible for any of it - since Hindus are not Buddhists.
Missionary religions are simply a nuisance. Further to the west, the GrecoRomans fortunately didn't take to Buddhism greatly (it was an alien religion in more ways than one) and stuck to their Gods like reliable, loyal, sensible people would. And so, one doesn't hear of Zeus and the other GR Gods being "bodhisattvas" - which of course they aren't and wouldn't ever be. The Persians more significantly commented on the push they felt from the east by Buddhism, round about the time when they found themselves beleaguered by christianism that emanated from the west. (I don't know their particular reasoning for feeling concerned by the onset of Buddhism, but it may have been incompatibility with their established religion, Mazda Yasna, and the fact that Buddhism was very missionary.)