Although the religious right is a determined group, at some point they must show actual human beings who succeeded through "self-determination" at becoming heterosexual. Until then, they might as well be defending the right of a goat to become a unicorn.
Before the American Psychiatric Association declassified homosexuality as a mental disorder in 1973, aversion therapy was used routinely in hopes that it would prevent or eliminate homosexual behavior.
Bondage. From the point of view of some gay men, and perhaps some women too, it may very well not be a bad thing at all. Whatever tickles your pickle, right? But in the evangelical Pentecostal church in which I grew up, a different type of bondage was a very bad thing indeed.
Exodus taught that gays and lesbians could either change or repress their sexual attractions through a process of prayer and counseling. So its disappearance is a major change in the ex-gay ministry landscape. But the ideas behind Exodus' ministry continue to thrive.