Why dont you go to Africa and look around? If you think AIDS is a gay problem, then I hope no one ever sleeps with you.
Promiscuity, either natural relations between men and women, or unnatural between two men (or two women), leads to all manner of diseases. But it is a fact that anal sex spread AIDS more than vaginal sex, although that is risky as well, obviously. But you know this.
Some residents of various African countries also practice other nasty stuff like "dry sex", screwing young boys on the side (or young girls or even babies), endemic adultery, and so on. All of that will help AIDS spread. It's all ethically and morally reprehensible.
That does that make you feel better?