I know what you mean and it is really sad to observe that. The struggle between the absolute need to appear compliant and the temptation of actually thinking for them selves. The frustration that this causes and the evil results in the release of this frustration.
Fanatics are every where in all sorts of political and religious believes but some religions tend to produce more than others. Perhaps is, as you said, the insistence in not changing human instructions given centuries ago in totally different contexts and taking those human instructions as if they were divine.
There is a clear problem in certain religions, I still don't know if it's the religion itself, the culture where it proliferates or a mix of both!
Whatever the problem is, the world is suffering with fanatism!