Swearing is a part of how people talk. It's not as if I add 'fuck' to every other word I say for the sake of saying it-it's just as much a part of expression as any other word, and purveys a very specific vibe, albeit not a positive one. I'm not going so far as to say that everyone who swears does so as a means of expression via the English language, but I think that restricting it for the sake of an audience that the rating system already precludes is a bit prudish, really.