I rather agree with the OP. Just because we can remain anonymous behind a computer screen doesn't mean that we should be blind to the fact that there are real people behind all those other computer screens. It doesn't hurt to be civil, even when disagreeing with others. I actually don't get the thrill of being able to hurl insults just for the sake of it, and just because we can.
As in real life, some people can irk me to the marrow, particularly those who are mean-spirited, deliberately annoying and rude for the sake of it. In response, I can certainly return fire, especially when I'm pissed. But usually I try to treat people, even computer people, the way I'd like them to treat me.