@Abaddon I think it's okay to call someone names as long as you also have an argument to go with it. I probably wouldn't just call someone a fag without an argument, unless that person was such a fag that everyone else could easily tell. At that point I'm not trying to win the argument with that person, but to show the others what the real issue is.
There's a time and place for gentlemanly rules (maybe with duelling), but oftentimes people will criticise someone for his poor manners when they can't beat his argument. So it can go both ways: calling someone a fag to get out of an argument, or complaining about getting called a fag.
Or maybe I'm just tired and don't want to write out a bunch of paragraphs when a good ol' ad hom does the job.