Opposite of it , manpads are mutually assured ban but Indian fear if they use Choppers then new weapons will flocking in.
One factor is altitude and morality of it , i wish to know the reasoning and not my assumptions.
Heliborne operations are undertaken. But air support is not undertaken as that shall result in extensive collateral damage.
As for why there is no vertical escalation in the valley by either side - I gave you the Indian rationale above, and for Pakistani side, rationale is simple - it keeps the costs for them down, both economically and politically/militarily.
There is a whole economy built on the insurgency there, where the Kashmiris who have the power, are loathe to allow peace to return.