Why did ancient Indians convert from Hinduism to Buddhism?
Answers
Yes. Many of them returned back to hindu fold, after they lost the patronage of the kings, as well as wealthy household.
The vast Sangha of the Buddhism was an unproductive unit, with many mouths to feed, and less to work. No society can look after so many people, who did not work. The kings used to support the Sangha in the early days, but later on, it became a drawback on the state revenue. Thousands of people lived in the Sangha, and wandered out in the noon, to collect food from the householders. The society was unable to look after a large number of monks.
After the royal patronage ended, the Buddhists had nowhere to go, but crawl back to hinduism. They were accepted by the hindus.
The hindu religion was not that much orthodox in those days to refuse them. The schools of Indian philosophy, that of Vedanta accepted them, and as a gesture of goodwill, accepted Buddha as the ninth incarnation of Vishnu.
The modern day neo Buddhists preach this as an annihilation of Buddhism, and condemn hindu religion for the same. A few of their publications, from the Dalit Buddhists, have written small pamphlets declaring that the Jats of north India were one of those who were converted from Buddhism to hindu religion in those days. These are available with publishers of Dalit literature.