I don't understand your POV - if pro-seperatism leaders exist then so do pro-India leaders, along with all the other machinery and resources of the Indian State to provide a counter narrative to the separatist one and win over the Kashmiri hearts and minds. The resources at the disposal of the Indian state dwarf anything Pakistan can put into it. Yet, according to you, 'propaganda has brainwashed the common folk.
If propaganda from an entity that has a very limited presence in the territory and limited resources is responsible, then it essentially points to failures on the part of the Indian State, and perhaps to the fact that it is not 'propaganda' that is the cause for separatism but a genuine resentment of continued occupation and a denial of the right to self-determination. If the latter, then continuing to refuse to commit to self-determination and continuing occupation will only perpetuate that resentment, not alleviate it.
Being supportive of a referendum does not mean it has to be held today. In another thread we argued that the Indian government could with Pakistan to hold a referendum 10-15 years down the road provided certain benchmarks were met in terms of peace and stability in the Kashmir valley.
Such a move would be an enormous incentive to normalization in the territory and regionally, and would provide additional space for India to win hearts and minds in Kashmir.