I don't think you are aware about Kashmir's situation prior to the abrogation of the article. Stone-pelting(sponsored by seperatists) and murder of civilians by terrorists were common. There is also significant amount of Pakistan-backed propaganda in the valley. Pakistanis have already flooded the internet with photos/videos from Syria, Palestine etc. and are claiming them to be from Kashmir. Considering this, what do you think would've happened if communication was fully open?
Is the communication blockade bad? Yes.
Is it necessary to keep the peace? Yes.