To a certain extent it’s a ‘how people talk about maths’ thing, and a what the starting point was.
When you look at the actual numbers. There are still more men being infected than women. But the gender difference is shrinking.
It’s not a ‘male’ specific disease. It’s comparative historical prevalence in men comes from unprotected anal sex being highest risk sexual activity for any kind of disease transmission, monogamy being less common in gay men at the time of HIV peaks compared to in heterosexual relationships, and condom use being comparatively lower (as no pregnancy considerations).
That combination lead to HIV transmission rates being very high prior to the public health campaigns taking effect. Result being more people is society who are infected and can therefore transmit. More opportunities to catch it.
Targeted Public health campaigns have been very effective at both reducing tranismission and increasing detection (which then further reduces transmission) in the gay male population. But straight men and women mainly assumed it didn’t apply to them. Transmission still occurs - and as more women and straight men have become infected, that transmission route slowly but surely results in more cases.
eg. Straight women on pill, has unprotected sex with man who is not aware has HIV. She doesn’t see him as being a risk because he gives a good chat on how has had std checks / doesn’t sleep around. She’s confident on contraception which is her primary concern. Gets infected unknowingly. No symptoms. Doesn’t realise. Repeats this with a handful of other straight men. None of this group have any risk awareness as dont think hiv applies to them. And other stds and pregnancy have symptoms. No symptoms - so think they’re fine.
Slowly but surely that transmission method gets around a new population, who aren’t risk aware. So women who earlier on very rarely got their ugly bits uncovered anywhere near someone with hiv, because it was almost exclusively a feature of the gay male community are now both getting it and transmitting it. From almost none to some is a big rate rise. Even if total count is still lower than men. Whereas gay men used to be high numbers. Awareness has brought that down. So rate is falling. Although falling rate from high start can still mean total is lower than women even if women’s rate is rising.
Impact of trans vs total population, negligible.
Impact of bisexuality, and individuals who had sex both with men and women - significant in enabling the disease to cross over between population groups. Impact of straight people assuming it’s a gay disease and thus not relevant to them. High.
eg. Ask yourself. Have you ever considered you might be an aysymptomatic carrier? And if not, why not. Same question on female friends who’ve been in long term marriages. Or recently divorced. . (No need to answer, but it’s enlightening).