Your point is incredibly important. Over a century of clinical data shows us definitively that conversion therapy does not work, and that it's harmful to people's mental health. So getting rid of it should be a no-brainer.

Unfortunately, almost all of the people who support conversion therapy are religious, and they don't accept data and evidence in the sense that non-religious people do.

They believe in things like magic and faith instead of reality, so they keep insisting that reality isn't real.

They push conversion therapy by insisting a god, usually the Christian one, will intervene — despite indisputable evidence to the contrary.