Commentators about the decline of buddhism in its native land
should read the excellent work by Swami Dharmateertha titled Shankaracharya and counter revolution. It is a revealing commentary on how the so called hindu revival under Shankaracharya was an unvarnished campaign to root out buddhism. All means fair and foul were adopted. The revival was essentially was nothing but the reestablishment of stranglehold of caste in Indian society for which the socalled Adi Guru is to be held in blame. One can only be astounded by the arguments put forth by vested interests when they posit the view that the benevolent religion buddhism declined due to
1.) The corruption of buddhist monks and the disconnect with the masses.
2.) The Islamic invasions.

Both the arguments are notoriously hollow because if it were true then Hinduism should also have long disappeared. The arguments put forth should have been all the more stronger reasons for the disappearance of Hinduism.

1.)If the monks were corrupt the hindu priests were nothing but corruption embodied and also the stifling caste restrictions imposed by hindu priests would have been sufficient reason for the common populace to renounce hinduism and embrance more egalitarian faiths. Also while it takes ages to adopt new practices it is also equally difficult to let go of dearly held beliefs without an equally compelling reason. And surely renouncing buddhism with its promise of compassion and salvation for all to a faith which mistreated a great number of its supposed adherents would be nothing but a figment of imagination of an incredulous or devious minds. So one can safely argue that if at all there was transference of faith to Hinduism in other words Brahminism would have happened under great duress and violence like what is happening in the present times in tribal pockets of Orissa etc. by Hindu revivalists. There must have been unprecedented violence unmatched by Islamic fanatics to wrench the masses out of the Buddhist fold.

2.) The second argument that Islamic invasions resulted in the rapid decline although sounds a little more convincing rings hollow to explain the total disappearance from its original land. For if islamic invasions alone were responsible then Hinduism should also have disappeared along with it for both had to face the brunt. So what must have happened is that Buddhism was already in a terminal state because of the onslaught of Brahminism which used violence to root out Buddhism and was already in rank minority by the time of Islamic invasions. This explains why the followers of Brahminism who were the teeming majority at the time of Islamic invasions survived.

From the above we can see the major and the overhelming cause of decline of Buddhism rests with Brahministic violence and not other reasons.