Though I've grumbled about anonymous, mean-spirited/catty comments left on blogs and message boards, I don't think I've ever hated all anonymous comments. If the comments are valid and mature, and allow open discussion without too much defensiveness, I see no harm. Deciding to post multiple comments in Jason's blog post about Engine Down/post-hardcore/emo, I've found the discussions to be pretty engaging. And this all reminds me of why I bother skimming through comment sections in the first place.
Back when I was a regular on the News Askew board, I always thought it was cool whenever Kevin would post and answer questions if he had time (I believe he still does this, but it's been a long time since I've been on there). This way, there's something that goes deeper than fancy, super-carefully-worded press releases. Of course, Kevin has shot his mouth off and paid for it later (the supposed "feud" with Jon Favreau, his dislike of Magnolia, etc.). So, I try to watch what I say.
The thing is, I like engaging in conversations with people that are interested in what I'm doing with the book. Out of all the conversations I've had with people in the past four years, I've only really run into one big sourpuss in person. Though there were others with that Viva La Vinyl thread, I can't say there has been much resistance to what I'm covering.
And that's what been appealing about venturing out into comment sections. If people are willing to discuss stuff openly, then why not? Plus, if there are those that choose to be outwardly negative and bitch, it lets people know this isn't some secret bitchfest.
To me, I can't expect people to know exactly what's going on in my head. I can't fault people for having a different interpretation on the topic. I find it discouraging when authors want to rip readers apart for not understanding everything they wanted to put across.
As somebody who has felt ripped apart because I didn't interpret everything exactly as a certain person wanted to convey, I try to go light on the people who read my stuff. I'm still thankful anybody wants to read my stuff. Besides, why should I vomit and spit on a sounding board that might help me stay grounded? But for those that just want to start some sort of virtual fight because of factors that have nothing to do with the topic at hand, I just skip to the next comment.