Let us see what Amebedkar says about anhilation of Buddhism from India.
> Such was the slaughter of the Buddhist priesthood perpetrated by the Islamic invaders. The axe was struck at the very root. For by killing the Buddhist priesthood Islam killed Buddhism. This was the greatest disaster that befell the religion of Buddha in India. Religion like any other ideololgy can be attained only by propaganda. If propoganda fails, religion must disappear. The priestly class, however detestable it may be, is necessary to the sustenance of religion. For it is by its propoganda that religion is kept up. Without the priestly class religion must disappear. The sword of Islam fell heavily upon the priestly class. It perished or it fled outside India. Nobody remained to keep the flame of Buddhism burning.