Should music with curse words be allowed at school dances?

I have never understood the concept of shielding kids from things in society that they will grow up to experience everyday.  What’s the point  of never showing kids curse words or protecting kids from bullies if when they grow up there still going to be curse words and bullies?  On another note, why are curse words bad?  What harmful effects does saying curse words have?  The only problem is adult’s twisted morality that claims saying certain words is morally wrong.  Curse words are just words.  When you say a curse word, some baby puppy doesn’t die.  All that happens is somebody hears it and may or may not be offended because of their morality.  Furthermore, do the people organizing school dances really think kids don’t experience these songs?  They know all there is to know about these songs.  Basically, if those songs wouldn’t be allowed, students would be shielded from something they already have experience with, something that has no bad effects, and learn a little bit less about the real world.