Ass and Hell aren't considered bad words by the FCC anymore
It's interesting how some things that were previously considered obscene are now considered "fine," or some things remain obscene in the U.S. but not elsewhere, and how what used to be considered "fine" is now considered obscene.
For example, you already explained the first point. As for the second point, no one in Europe batted an eye when Janet Jackson showed off a certain piece of jewelry on a certain part of her body because European TV shows bare breasts all the time. Well, not "all the time," but, after a certain hour, it's no longer unacceptable to show them. As for the third point, FCC regulations for sex and sensuality have become so much stricter, while language is becoming more permissive. For example, Homer Simpson once could walk around with no pants on all day long. Now, even his bare derrière has to be covered up somehow, or the network will pixellate it. A cartoon butt!!