Swearing in films is like violence in films: if it fits the plot and is used "as appropriate," no problem. "Goodfellas" is a good example. If it's gratuitous (as the use of "f-bombs" in standup "comedy" shows on cable), I don't like it.
I agree that the gratuitous use of f bombs, n bombs or anything else is neither funny nor appropriate. That said, however, sometimes the censorship we endure is worse than the actual use of certain words. What comes to mind immediately is the line in the Godfather cleaned up for television in which Sonny announces he doesn't want Michael coming out of the bathroom with "a stick" in his hands.
