Your link doesn't say what you imply it does, only that promiscuity is not the ONLY cause. Which is true, anal sex (vs. vaginal) and role switching are also huge factors, as evidenced by the study they reference.
"However, according to two large population surveys, the majority of gay men had similar numbers of unprotected sexual partners annually as straight men and women."
In 2007. Gay male promiscuity has been on a steady decline since the 80s, the time of the last epidemic. Honestly, using 2007 data for the 1980s is like saying that people didn't get sick of cholera from drinking out of toilet water wells because no one does that today.
The vast majority of people are not having anal sex, which is a more common practice among gay men. Anal sex is an incredibly effective way to spread AIDs. I don't understand why this is controversial. Promiscuous anal sex between men is a risk factor to spread AIDs. Promiscuous straight couples typically don't have anal sex.
Moreover, as your study points out, 'switching' who is in what role in anal sex is another effective way of spreading AIDs. Women cannot be the penetrative partners in anal sex, so even if a woman contracts AIDS via anal sex, she cannot spread it as a penetrating partner.
But to directly contradict your false narrative. I'd point out that your study was done in 2007. That's 13 years ago. Gay male sexual behavior in 2007 greatly differed from that during the AIDs epidemic. By choosing to use an article from 2007 to explain away gay sexual behavior during the AIDs epidemic of the 1980s, it is clear that you are trying to spin a narrative instead of actually look at events. In the book "and the band played on" by Shilts, the number of partners recorded during the 80s among the minority of gay men who had AIDS was regularly in the hundreds. This is clearly more than most people -- gay or straight.
Like I said, AIDS is a disease that affected a relatively small amount of people who continued to live life as normal because they could not control themselves. This furthers my point that people are not necessarily willing to sacrifice life's pleasures due to a deadly disease
https://www.medicalnewstoday.com/articles/82330#3