A near-majority of gay men were sexually molested and abused as children (~40% according to most studies). There is a reason they want our children.
I'm no psychiatrist but you see the same phenomena with the sons of physically abusive fathers who end up becoming physically abusive themselves.
You should be glad that you`re no psychiatrist But on a serious note, I am saying that you can be born (and/or develop after birth) with a more female brain (in a male body) and other organs as well. So I don`t buy that you can`t be born gay to a certain extent. But there are also developmental inputs like the one`s you mentioned also. It`s hard to deny that some dykes and fags are morphologically more similar to males/females than heterosexual people. So there is a definite alteration of the individual during development, I believe caused by these endocrine disruptors as mentioned.