Interesting, to me, that you qualified your mention of heterosexuals with “a lot of” but did not qualify your mention of homosexuals at all. Those who are (I’m assuming) different from you must all be the same? Please ponder that for a while. Also I question the percentage of heterosexuals who actually do feel revulsion at gay sex.
The answer to your question is that, just as in any grouping of people, individuals are different. Just as there is a spectrum for sexual attraction there is a spectrum for sexual revulsion.
Here’s what is wrong with “gay-conversion” therapy: no-one knows or can prove scientifically what causes sexual attraction, gay or straight. The best that anyone has come up with so far is correlation, which is never predictively 100% accurate, but just seems to change the odds somewhat. It’s clearly a very complex set of factors. It’s also clearly something that is usually set pretty early (I realized it when I was 7).
So what kind of process could “gay-conversion” therapy possibly use that could overcome enough of the contributing factors that have been in place for any gay person for most of his/her life, to make such a fundamental change? And make no mistake, sexual attraction is very much a fundamental component of personality.
A gay person who dislikes being gay can be celibate; some can force themselves to have sex exclusively with the opposite sex; a bi-sexual person can presumably choose one sex over the other all the time. That’s not conversion, that’s just a strong force of will.