I think there is a knee-jerk reaction to "acquired homosexuality" because it was used so long a an excuse to persecute homosexuals. But like many arguments in our society, I think it is the wrong hill to die on. Because to overly concern oneself with winning the argument over whether homosexuality is acquired or not somewhat cedes the ground to the authoritarians. It implies that there is something to be lost if homosexuality is acquired. That if it were, we should probably then accept some regulation of the sexual lives of consenting adults.
I do understand there is a purely scientific interest in many questions. At the same time, this seems one of those questions that's very easily confounded by a myriad of social factors.