We can't know for sure whether they are counter-productive - would there be more islamists without the Chinese policy of repression? Would there be more attacks? We can only conjecture.
There probably wouldn't. What perturbs people here about this approach is that it works despite going against the principles of liberal democracy; it's the first time an oppressive regime is not led by dunces, and it's working fine. That, + the fact that most nationals don't really care much about surveillance as long as it helps maintain civility and cohesion.
Its far from the first time, the issue is that when things go wrong those in power can't be replaced.