I'm going to take a right turn and upset the linear thinking a bit.
Knowning the Muslim community better than most. Though I have to admit most of my aquaintances are from the middle class and aren't particularly religious (very few fanatics).
The reason may be religious, but more likely it is just a form of negotiation. Or better said, bargaining. Take a persons rules and/or regulations and use them to gain control over the situation or the negotiation. I really don't know why so many people feel compeled to compromise. But you can bet, a sharp negotiator will use this trait to gain control and empowerment.
Trickery more than anything else. No camels to steal, so they do the best they can, with what they got.

Just to get the whole thing in perspective, a leader of the Muslim community, more social than religious, gave me a whole set of John Wayne CD's, for Christmans. Generally, over the years I've gained there respect. Parallel social structures, that aren't actually in conflict, most times. But work a whole lot better, with a little mutual respect.
Mutual respect doesn't mean you have to eat there crap and like it.
My religion is just as relavant as anybody elses, my social structure just as kindred, my color just as significant. Don't start no chit, don't take no chit.