To me, one of the most appealing things about internet communication is the removal of real-life communication problems like the existence of such things as gender, race, religion, and age. Unike in real life, we're all black text on a white background here.
I do see your point, though, as anonymity carries with it an implied (and very real, in some aspects) lack of "responsibility" for one's conduct. But it's one of those things where the price is worth the benefits.