They may want to back out of that one too, especially if society gets to the point of designer genetic children. If there was a "gay gene", and prospective parents decided not to raise a pervert in their house, then that child may become murdered through an abortion. (ahh, the fun with flexible morality)
It is in the best interests of homosexuals to either start now and ban genetic testing for "queerness" or declare "we don't know" in regards to how one's sexual orientation is acquired. Personally I am a fan of the "sin nature" theory.
But lets be perfectly clear, not all people prone to alcoholism became alcoholics. Many people who do become alcoholics overcome the destructive lifestyle of alcoholism and spend their lives fighting those urges in order to live a normal life.
At the same time many people who are NOT alcoholic nevertheless descend into alife of destructive alcohol consumption.
A lot of people who fall into lives of alcoholism are brought into that lifestyle by their peers (dare I say recruited?), especially when they are young.
All of the above applies to gays if there is such a genetic predisposition to that kind of perverse and destructive behavior. Nothing says they HAVE TO succumb to that unhealthy lifestyle however. They can overcome it and return to leading normal and healthy lives, fighting off the destructive urges with the help of family, friends, and most importantly Faith.