Because you have fallen into the liberal trap of equating homsexuality with immutable trates like left-handedness.
Homosexuality is filthy perverted behavior and nothing more. How and why they came to engage in that behavior is best left to psychiatrists whos study pornography, arson and other forms of sexual deviancy.
I think it is obsessive compulsive behavior, pscyhologically, and the realm of psychology has ALSO been infiltrated by homosexuals to the effect that it's now taught to be some "natural" sexual state of being...just as public educational systems now teach and do so to even early grade school age children (all of which is are examples of the problem, not the solution). I've heard and read what the leading Bishop of the Episcopal church has to say about humanity and he says outright that he'd "rather serve in hell than be in heaven with people like that (Christians who rebuke homosexuality, and that statement is about Christians in and ONLY about Christians as to the issue of homosexuality)."
So, here you have a corrupt person sitting as leader of a group of people dedicated more to arriving in hell out of determination to proliferate an evil, rather than reject their sin and return to God.