BWolf:Whatever happened to polite disagreement?

Good question, unfortunately. Why does disagreement seem to lead so frequently to insults, or even demonization, these days? Whatever happened to civil discourse? Aren't common courtesy/derech eretz and respect for another individual/kavod habriyot considered virtues anymore? To say that a person is incorrect is one thing, but to call him/her evil simply because she/he holds a different opinion is character assassination/motzi shem ra.