Oh, I agree with you. You don't have to be an ass, just because you're anonymous. I didn't troll, either, but I did find that I felt more free to comment on things I otherwise wouldn't for a variety of reasons.
That's certainly both good and bad.
The negatives, in my case, were that I would end up getting into discussions over trivial topics, or would end up reading tons of comments, some good, some bad, and comment on them just because I could.... For example, if I disagreed with you, I would tell you, event hough most of the time it was over things that just weren't worth the time and effort of getting into a debate with a random stranger over.
On the other hand, posting anonymously also gave me freedom to talk at length about things that matter to me but maybe aren't the best things to go talking about using my real name when everything is indexed in a search engine (politics, religion, etc.). I'll certainly stand up for what I believe in, but in cases like a potential client who may be looking me up on Google, my religious views, for instance, shouldn't be the first thing they find. It's just irrelevant in a work relationship 99% of the time.
So making the switch to my real name, I did lose some of that freedom, and one could argue that this is a bad thing, but for me, the constraints it places on the types of discussions I'm willing to have means better time management and (overall) more thoughtful responses when I do respond. I suppose if there was a real hot-button issue that I felt compelled to comment on, I would create a throw away account and do so, but sticking with my real identity forces me to think and evaluate those situations more closely before doing so.