good point. however, for the first ten years or so, people didn't realise it even existed, as that was the incubation time for the virus. so they were innocent, in as much as they didn't know not to go bareback.
you're right now, though, of course. but people just don't think anything's going to happen to them, gay or straight - look at how many teenage pregnancies there are, and the upsurge in cases of other STIs. people are just daft, irresponsible or deluded, whatever their sexual inclination.