Why do people still think homosexuality is learned?

I was skimming through The Economist the other day and came across this article about gay individuals in China and the day to day obstacles that they have to go through. The article shared the story of one man who struggled to come out to his parents and instead of being true to himself and being him, he underwent gay conversion therapy to try to fix himself for the sake of his relationship with his mom and dad.

And guess what? As a result, he got anxiety issues, insomnia, weight and hair loss, and minus $1,700 from his savings account. But the thing that he went in to "fix" still remains. He is still a gay individual. So this brings me to my question: if homosexuality is a learned behavior, then why doesn't gay conversion therapy work, like ever?