Dirty words.

Words don't really do much harm. Okay, well, they do, but that's not my point.
And these "dirty words"-- the ones we all know and love usually mean "poop", "butt", "sex", or "curses".
So why, when we say them differently, are they suddenly so horrible? And why are they even in existence? Just to challenge us and make life more difficult?
I mean, if you didn't have to shut your kid up every time he said "frog" because he mispronounces it as "fuck" life would be so much easier, no?