In the 70s, the DSM national diagnostic book contained homosexuality as a mental decease, and doctors worked on finding cure for it. Then it was removed. Why is that? Who are the people who want people to be sick? This time it couldn't be the doctors because they lost their funding. Any theories?
For the same reason we used to subdivide the human race into four racial categories but now we do not: advancement of scientific knowledge.
In case of gays, it was found that homosexuality isn't a mental illness, but a natural product of birth and/or natural development. There is no "gay gene" just as there is not "straight gene", but there is no way a person can be
cured of either sexual preference.
As for race, similar advancements in genetics revealed that, although all humans are 99.5% identical, the 0.5% involved a lot more variance than skin tone alone could account.
Science is knowledge and knowledge is power.