I wouldn't recommend it for kids, but for teenagers sure. Most of the ppl I run into in game are teens. And if you're freaking out about the language --- well, you haven't been in a high school or watched tv lately lol.
Sure! Curses should be allowed on television, movies, radio, and even here on the DIS. In fact, they should start putting curse words in advertisements and billboards because hey! People probably hear this stuff all the time, anyways.