I believe it can be both. I have not studied this closely by any means, but an educated guess would be that 1-2% of the population may have a biological component that would give them the "affliction". The rest are primarily young people(or began as) sucked into a perverse behavior by abuse and by a culture that says anything goes, and who are you to judge the "officially state accepted"(PC) behavior of anyone?
Either way, the vast majority of these people have extremely compromised moral principles, or none at all. They see a moral, ordered, healthy society as a threat to their primary personal identification and source of sexual gratification.
Exactly right. First and foremost, homosexuality is about sexual libertinism, the obliteration of all rules related to sexuality. Without this underlying philosophy, their agenda crumbles.