I don't think gay people choose to be gay. Listen, I know the arguments both ways - I know, I know - but who would want to choose to be something that would get the rejection, ridicule, persecution?
Quick anecdote: I know a guy who is a Doc. One of the smartest and and most capable people I've ever known, we've been friends for over 30 years. He's gay. He always was, but he hid it, was mostly celibate, tried to deny it, but has always thought he was gay. He says he knew when he was at puberty, and didn't want it. He is a Christian. He got married, tried to 'go straight', all that... now twenty years later it comes apart. He's got a wife and three kids, she's leaving, he's unable to fake it anymore. He's still one of the best men I've ever known, and he doesn't deserve anyone's contempt.