You could be right, but this was (is) during the time in which the gay community had to fight against being outcasts of society. On paper your comparison with male breast cancer can be somewhat valid, but obviously there are no negative consequences for just pushing awareness for women. While on the other hand pushing MSM as being the "only" ones getting HIV could result in some serious social stigmata and slowing down acceptance etc.
However, yeah, maybe the awareness should have been more targeted to address the specific groups, but still avoiding mention that in non-targeted material for the general public.
In the graph you can see that (straight) women are much higher at risk than straight men. Which makes sense because closet MSM boyfriends/husbands will infect them and/or they are more likely to be at the receiving end of anal sex. Poverty (thus education about prevention etc.) is another factor as seen by the higher amount of black women.
I would guess the majority of the few non-black straight men in that statistic got infected from sharing needles (and possibly blood transfusions), which is an entire different thing to warn about.
Though maybe now is the time to scare people a bit. I mean, if a third or more of my dating pool were "contaminated", I would have to question how to have sex at all, even with protection.