Why are all the people on yahoo answers douchebags?

Ive been doing some research, and I've come to the conclusion that half the people on here are completely disrespectful and very ignorant. So say, I ask a question on a topic that's meaningful to me, as an example, 'smoking marijuana'. The question will be something simple like, "why does everyone have a bad view of stoners in society?," and I'll get answers like; "because you guys are *****'s," or "because people who smoke think they're cool, but really are just pathetic," etc. I mean I just don't understand why someone could be so rude. I know that people can have their own opinions, but there's no need to be that negative. Basically I want to know, why bash on someone for something they do when you'll most likely never meet them?