There was a big article in Rolling Stone sometime back about this. Basically, these guys have serious mental problems; they are royally screwed up people who are seeking attention and somehow have the misguided notion that they will be part of an "in crowd" if they catch HIV.

The Rolling Stone article included interviews with guys who had caught "the bug" and now realized how foolish they had been, because of the health complications, medication regimen, etc. that they had to follow.

I wish good quality counseling/therapy was available for everyone who needed it, because I think a lot of the people who get HIV and don't intend to are people who have esteem problems and don't feel assertive enough to ask their partner to use a condom, or are the "bug chaser" types. Some are just simply playing the odds, and perhaps that's their choice, but I really wish the ones who are making those decisions because of not feeling good about themselves could have access to the assistance they need to be able to make healthy decisons.