This is demonstrably not true. The odds of a man getting HIV from an infected woman are something on the order of 500-1 per encounter. The odds of a man getting it from an infected man are closer to 3-1. The odds of a woman getting it from an infected man are about 50-1.
AiDS may have began with homosexuals, but no longer is it the only way to get it.
I never said it was the only way to get AIDS. However, there is no "better" way to spread it than through male homosexuality, not by several orders of magnitude.