stds on the whole are most easily spread through unprotected anal sex. especially those spread through blood and other fluids. there was also the difficulty of safely having a long term gay relationship at the time among other factors that led to gay men trending to have more hookups than most demographics.

it's not that aids targeted gay people, it's just that gay men In that era were more susceptible to stds in general. this was just the first time it started killing people en masse. and, as obvious as it may seem now to wear a condom, at the time we didn't have the research to tell us how it actually spread or that a contraceptive could stop it. when you think of the condom as a tool to stop pregnancy it's hard to reframe that as a tool for gay men to be safe. especially since it makes sex feel less intense. the government certainly wasn't interested in studying it to figure that out.

as far as I understand that's all that really changed too. we learned how it spreads and some basic tools and techniques we can use to mitigate that spread. it's still a terrible disease, but that alone brought it from genocidal to what it is today. still dangerous, of course, but not killing people by the millions.