One of the problems not discussed, is the fact that India is a highly religious society with centuries long history of intolerance towards non-Hindu faiths. And while Indian Hindus would like to promote a more stoic or spiritual view of themselves, we only have to remember that over a million people died due to religious violence during the Indian/Pakistan partition of 1947, that Mahatma Gandhi was killed by a nationalist Hindu group (directly because of his tolerant philosophies towards Muslims) and that violence against Christians (and Christian missionaries) still continue.
This being that case, it should be hardly surprising when violence against Jehovah's Witnesses occurs, as it sadly seems to be a more justifiable response to religious conflict, in the minds of some Indians.
Religious violence in itself however is an interesting topic, and while most people would put it down to ignorance and poverty (which would seem to fit in problems of the Indian subcontinent), it more exactly the product of a perceived imbalance of power and a lost of authority. Thus when a person or a group feel like they have been marginalized by another group, then animosity grows ... which sometimes results in violence.