No answers here but yeah i've noticed the same. Comedy central is full of it. But the oddest thing for a religious person like me, knowing where judaism originated from, I always found it odd how full of profanity the shows are which are often associated with jewish backgrounds. Its weird because all these so called jews are doing the exact opposite of whar judaism propogates. Its almost like the religion has been hijacked or something.
My 2 cents i guess
I don't think there's anything in the Jewish religion that prevents "swearing." Not any more than in any other religion, anyway.
Anyway the answer (And not to stereotype any one group of people, as there is no "rule" and of course not everyone falls into a set group or behavior) is a few different parts. First of all, being Jewish is a bit of a chore, lol. There's far more religious education required than many other religions, preparing for a Bar Mitzvah is insanely hard, and Jews have a very distinct culture that existed lonnnng before the religion even existed, and it's definitely not a mainstream culture, lol. So yeah it's pretty easy for Jews to sorta look at where they came from and their place in the world and be like "what the fuuuuuck? We got screwed." And I think that's why humor's always been a pretty major part of the Jewish culture.
It's important to remember that unlike other religions, the Jewish people were a people BEFORE they were a religion; they were in the desert as slaves and were eventually freed and the religion itself was developed soon after. But as a people before the religion, they developed their own culture, practices, languages, etc. So in a way Judaism can be looked at almost as much as something like Italians, or other ethnic groups, instead of just a religion. Christianity on the other hand doesn't have a "culture" that pre-dates the religion, the religion and the "Christian people" were basically created at the same time. (The earliest Christians were pretty much all Jews, actually.)
So anyway, lol. A convoluted explanation. In fewer words, the answer is that Jews enjoy laughing at themselves and there's a good deal of humor in the Jewish culture.
I mean there's a lot of things like that. Italian comedians usually joke about being Italian, black comedians about being black, etc. It's pretty much the same thing. That's what makes Judaism different from other religions, its pre-existing culture. I have though seen Catholic comedians joke about various aspects of their religions and upbringings too, I just don't think it's done as much because it's just such a more mainstream topic and idea seeing as how it's basically a majority.