No surprise here, I agree with Brad and Kajun. Here's why:
This account of mine has the greater potential to have comments I dislike posted to my comics. If someone posts, "Gay sex is disgusting," it might not be considered trolling since it isn't a personal attack and it probably relates to the content of the comic. Well, I've heard it all before and I write the comics to entertain myself most of all and my friends secondly. I don't make the comics to create a forum for people who happen to disagree with homosexuality for whatever reason and I'd rather not have it pollute my creative output.
In this thread you said of three of my comics, "they were fun to read in an expose kind of way, but not particularly funny to me." That isn't the kind of comment I'd trash, even if all you said was you didn't think they were funny. It's an honest assessment of the strips.
If I got negative comments frequently, I'd probably turn them off; but if it's only the occasional comment I don't like, I'd like to have the ability to delete it. As a moderator, I'd be able to delete comments anyway, so I'm giving an example of why someone might want to delete certain comments from their comics--maybe it will be a 14 year old girl who wants to show her parents a comic she made about school, but doesn't want them to see some R-Rated comment made below it.