Oh boy, you opened up the big one. There's lot of theories floating around here and other places. Plastic/rubber poisoning, MK Ultra Brainwashing, herd mentality combined with media conditioning, mental illness/neurological deficiency, childhood sexual abuse trauma, literal demon possession, etc.

Everyone seems to have their own personal answer as to why, but anyone who tells you it's natural is either ignorant (the literal definition not as an insult) or lying. Now having said that, the most common belief on here specifically, at least from what I can see, is that most derivatives of homosexuality are caused by childhood trauma.

Personally, I believe there's some merit in all of it. They all probably play a factor (including literal demon possession), but I personally believe that the biggest factor is mental illness/neurological deficiencies. There's a reason they campaigned to have homosexuality and its derivatives taken off the list of mental illnesses in the 70's and then turned around and started closing mental health facilities en masse and letting all these freaks into the general public.

I firmly believe they're all either mentally ill (Like Schizo type mentally ill) or have a neurological disorder. I also firmly believe there's a treatment for what's wrong with them, but everyone's been conditioned to believe it's "normal" and "natural" so even when it does come to light, they'll fight tooth and nail to stay mentally ill and unstable.