Well, to begin with, Leaving Kashmir valley no place in India is asking to secede. Kashmir was with India in 50s, 60s and 70s. Somehow from 80s and 90s, owing to AFSPA, they started to feel massively alienation. Also, Kashmiri are not wide spread in India and well integrated in Indian fabric. Unlike say Sikhs.
Interestingly, India also never attempted to integrate Kashmir or Kashmiri in India. 70 years of inaction has created an isolated community. But that also means a concentrated Kashmiri identity attached to their native land. It seems that political machinery of India was too busy in corruption and electioneering to integrate a vulnerable part into India, even at a people to people level. It was not that hard btw. Even now there are at most 2-3 million Kashmiri youth who could have been integrated into India. But that didn't happen. And I doubt it will ever happen.
It is simple: Kashmiri don't have much investment in India at any level. India only bit and chew Kashmir. It never swallowed it, let alone digest it. So, now the only solution is to spit it out. Let it go if you cann't keep it.