I suspect that most people who make the choice claim are bisexuals. Or just making the choice to be in the closet.

I still find it fascinating that the stances of the homophobe power base and the gay rights movement on this topic have almost perfectly reversed in the last 40 years.

Back in the 50s and 60s, this guy would have been saying that homosexuals are born that way, it is a biological defect, and his opponents would be responding "fuck you, I chose this."

I suspect that the truth is neither, of course. Different people have different sexual preferences for different reasons, and trying to come up with some grand unified theory of fucking is kind of a waste of time in the long run (though unfortunately necessary in the short run, since the current cultural and legal atmosphere in the west holds that only that which can be quantified is real, so quantification is vital to the process of breaking down obsolete 20th century taboos and replacing them with shiny, new 21st century taboos, even if that quantification is reductive to the point of losing meaning - hello Social Sciences).