Something that's always bugged me about the argument about whether being homosexual is genetic: Even if it is determined by nurture it would still not be a choice in the sense of gardening or skateboarding. Nobody consciously chooses the way nurture affects people, least of all themselves.
Even if it is proven that homosexuality is not genetic, that still does not imply it is a choice, any more than I choose to have certain sexual fetishes (which I'm guessing are not genetic).
Nurture would imply, however, that you can control the outcome as a parent and that raising a gay child (and the percentage of gays in the US anyway is estimated at less than 10%) could mean you did something wrong. People already make up all kinds of outrageous things to support the idea that there was something wrong about their upbringing, or to pass it off as a rebellious streak. The last thing any of us really need is the idea that, for instance, sexual abuse gives rise to homosexuality -- it really would not make things better.
Even if homosexuality were found to be a 'nurture' thing, it would hardly lessen the stigma. In fact, we'd have tangible places to point our fingers at just by examining the way a person was raised. It can be very much like the way hobbies/interests are developed in that manner. People who have inclinations towards art or music or sports don't necessarily develop those things independently -- for instance, if two actor parents give birth to a child, there's a good chance that child will be more exposed and encouraged to pursue the arts. It's really not a far cry, then, to say that Mrs. Jones' husband died, she then let her son take ballet where he was even further emasculated while lacking a male influence in his life, and suddenly you've got yourself a flaming homosexual. Certain behaviors and hobbies and interests can be encouraged and nurtured over time -- my parents were always very supportive of my artistic inclinations, which probably plays a big role into why I flourished artistically over the years. If someone wants to make a connection and say that a little boy was raised to be gay by his mother, I can just see the extraneous child abuse cases arising now by the religious right...
And, for the record, sexual fetishes aren't a great comparison. I'm pretty sure I have little to no desire for people to treat me and my sexual orientation the way they treat people with, say, foot fetishes. That is to say, not well at all. Fetishes aren't really looked upon kindly in the US.