It's also a choice. Lots of folks are predisposed to destructive behavior, but not all of them choose to act on it. Further, normalizing the abnormal doesn't help us, and our tolerance shouldn't be misconstrued as acceptance. That said, we're talking about human beings, and no human should feel forced to live their life in a closet.
I agree about the choice - but with a caveat. We can look at someone's situation and conclude, "They had a choice", but there are situations where the choice is rigged.
There are tons of theories about the origins of, for purposes of this conversation, male homosexuality. I disclaim any idea that this is an exclusive theory, that it explains every situation, or that it is infallible.
That said, the best theory I have read is from psychologist, Dr. James Dobson. I will give you the 101 version. He says that there is an important point in a boy's development that occurs at around 18 MOA. From conception to birth, the boy lives within his mother. Once born, she is food, comfort, and, well, everything to that child. Dad is just someone who may live in the house. Around 18 mo,, a boy will begin to notice that he is like Dad. In normal development, he will want to begin to spend more time with and identify with his father. Some mothers do not want or allow this transition to occur. In some cases, the father will reject the child or not allow the transition to occur for a variety of reasons. In many, many cases, there is no father to transition identity to. Dobson suggests that this creates in that boy a hunger for male attention, approval, and love. This desire is, of course, not sexual because children are not sexually aware at that age. As the boy grows, he has this persistent desire that has been present since he had memory (this would explain why many profess to have felt "gay" since birth, but, in fact, it can only back to the beginning of memory which, at the earliest normally, is 3 YOA). At some point in his growth and development, he will get exposed to someone or some entity who explains his desire as homosexuality, or he will learn of this explanation and accept it. It does make sense. It is very unlikely that he would run into someone who would tell him, "No. What your desire is concerns a desire for a father's guidance, acceptance, approval, and love. Deal with it in that context, and you will be heterosexual." So, the first and only explanation becomes the identity the boy assumes, and then he begins to act per his identity. In my experience, this explains a lot of male homosexuality.
Another chunk of it is explained by pedophilia. An older male sexually molests a boy. He doesn't tell anyone. He believes that he did something, or there was something about him, that caused this to happen. He develops with this sense that there is something inherent in him that explains the fact that he attracted his molester. Again, at some point, the answer provided is that he is gay, he adopts that identity and acts per it.
All that said, you will meet male homosexuals who had an ideal family, a close relationship with their father, and no history of molestation. So, there is no one explanation. Human beings are very complex in terms of psychology, behavior, and sexuality.
