I think it may have to do with religion, I know one of them sees cursing as a "sin"... so that could be the start of it.
I don't care for cursing myself, but I don't see any problem with it.. unless it's excessive to the point that it gets annoying.
I think curse words are mostly banned because the people who say them in class, outside, and public places like the library are usually very loud, rude and use them to insult other people which disturb busy people from doing something productive like reading, homework, listening to class lectures, work, and other important duties.
I can be loud, insulting, rude and disturb people without saying one curse word. Whats your point?