Uncle B might be able to shed more light on the proclivity.
It's interesting that barebacking and bugchasing have become a trope surrounding Gay sex culture, when the almost default position among many if not most straight people is condomless sex.
Yes there are Gay barebackers and bugchasers. The quantity of bugchasers is probably vanishingly small. There are billions of straight people who never even think to use condoms whose sexual behaviour is virtually unexamined and for which there is no publicly debated nomenclature.
I wrote
this essay six years ago, and it still sums up my feelings on the subject. It's not very long, but it is rather snarky and over-written (like so much of what we were posting at that time), so either slog through it or perhaps just this one paragraph:
This entire tale reminds me overmuch of the superinfected Tina twink, Patient X who bravely bottomed in a drug-induced gangbang in the sewers of New York until she'd managed to go from healthy to "full-blown" AIDS in a matter of months. The supervirus, like Bigfoot and Nessie, is more the creation of heated minds than scientific fact. Were I of the mind and had I sufficient volition, I could come up with a shocking expose on straight scatpigs or the ritual Satanic rape of virgin[s ...]. No one from the mainstream media would attempt to condone such behavior, and it would be dismissed as a sad aberration, however titillating.
It is impossible to discuss this exceedingly rare phenomenon without interjecting an almost reflexively-driven cluck of disapproval. I have had virtually no interaction with Seaside, so I'll not speculate on why she chose to post the OP, though I really don't think that she had any malicious intent.
FuzzyKen and I have extremely similar histories with one major difference: I was infected with HIV in 1984. I respect him (and his experiences) too much to engage him on this topic. I completely sympathize with him and his loss but we hold almost polar opposite views about it and the increasingly-common criminalizing of HIV in the US.
When I first started posting here I was very open about both being HIV+ and the fact that I abstain from condom use. The caveat here, and it's enormous, is that I'm a strict serosorter: I only have sex with bottoms who are already infected. I have suffered my fair share of trolls (including one who has followed me around from site to site) as a result, so I rarely post about it at all any more. But this thread is too important to ignore based on what's been posted above.
I have been extremely active, both sexually and socially at the bar I work in, for the past odd six years and have never met a chaser, whether online or IRL. This is important because I'm militantly out as HIV+ everywhere. If this issue were important in any appreciable sense, I'd have met one by now. I'm not denying that it never happens, but I can state with complete assurance that I've yet to be exposed to it, especially with the lurid angle of conversion parties.
What is infinitely more common (and I see frequently) are newly-infected guys who knew their risks and considered them acceptable. I do not agree with this line of thinking, nor am I condoning it, however I do recognize that it exists. Anything else would be to deny reality.
In my opinion, the biggest factor to this way of thinking belongs to those whom I label AIDS-minimizers: just take your meds and everything will be all right. The largest group of AIDS-minimizers are those with a professional stake in perpetuating it, namely Big Pharma and the medical profession. Sadly the second-largest group is the newly-infected themselves, but I don't engage them on this issue because life will have its leveling effect eventually.
My biggest issue with the minimizers, aside from the fact that they perpetuate a lie, is that they want it both ways: it cannot be a catastrophe to become infected if treatments are simple, stream-lined and risk-free. This dangerous distortion breeds a very casual attitude about what remains a terminal condition. Throw in some mental-health issues like depression and esteem issues and stir in a large dose of meth smoke, and it's natural that infection rates remain much, much too high.