Allah/Mohammed are not supposed to be depicted like EVER in any art and for the most part they arent but its much more common to see jesus depicted. Comedy is just comedy though and people need to sit the **** down and learn to laugh and let whatever 'sins' people commit be between THEM and GOD. not YOU+them+god.
Because the Islam religion is more strict. Don't y'all remember the bomb threats in New York because of that one South Park episode that made fun of Muhammad?