I find it helpful, before I hit POST on an angry retort, to check the person's latest posts. That can tell you alot about whether or not it would be worth your time to try to debate.
Well in that case, thanks for posting ;-)
Seriously, though, that approach can be somewhat ambiguous. They could always claim that the majority of their posts are so belligerent because they're intended to target what they consider to be unintelligent and anticonservative posts. On the other hand, a page full of unflattering comments from fellow freepers, available for all to see, would probably take a few of them down a peg or two.
I'm basing this on the assumption that most sane freepers (such as yourself, based on your comments) tend to avoid these types. As a result, threads with them on it usually feature only them, their small little band of cheerleaders, and those hardy souls that wish to go head to head with them and deal with their abuse. That makes it look like their numbers are stronger than they actually are. Having a feedback page can change that perception to something a little closer to reality.