Westerners rejected Greco-Roman Paganism, so they don't get to claim Alexander and Caesar? It isn't just that Buddha was born in India (Nepal is to India what Taiwan is to China), but also that the First Buddhist Council was held in the court of a King whose conquest would lead to the creation of India as a nation. It is deeply tied to both the political and religious history of India. To this day, the Indian government goes out of its way paying billions of dollars to secure Buddhist artefacts from private collections and auctions and bring them to India in the museums built near key historical Buddhist sites. Also, Indians did not "reject" Buddhism like how you rejected Paganism, Hindus name their children after Siddhartha, and continue to pay lip service to Buddhism in various ways.