Yes, I think some can be a genetic abnormality. But I believe that is rare. I am sure there are males that are simply born sexually attracted to other males, but that is not the norm. If you live in a culture where homosexuality is considered just as normal as heterosexuality, that it is encouraged and even celebrated. That if a father had a choice in watching his son on his first date hand and hand with a girl or hand in hand with a boy he would just toss a coin. It would be a non-issue. You will have more homosexual behavior.
Many would consider that a good thing. The blurring of genders and now, even race. That these are no longer a matter of biology but a matter of preference. There's a case where a man, because he gets rejected a lot of dating sites because of his age, wants to legally change his age from 60 to 40 years old. He says he looks and feels twenty years younger so why can't he.
If you can legally be a boy when you have a vagina, and that you're Black when you have not a drop of Black DNA, why can't you legally be any age you want? Why can't you legally marry anybody you want? Including your cat?