There has been shown to be a strong genetic component to alcoholism. Studies of identical twins, separated at birth has shown that even when raised separately and in different environments with regard to alcohol, there is a much stronger correlation between both twins being alcoholic if one is than chance. There has also, I think, been some efforts to identify some of the genes that might be the basis for this.
So should we now consider alcoholism normal and natural and to be accepted?
I am not equating alcoholism with homosexuality. I'm just pointing out that genetics is not always determinative of behavior. A genetic basis may indicate that someone is more likely to exhibit some characteristic or behavior than someone without that genetic base. This could be good or bad.
So far, no study has clearly demonstrated that there is a strong basis for concluding the genetics determines sexual orientation. At most there may, may be evidence that for some their genetic background increases their likelihood of having a same sex sexual orientation, but not determinative.
In any case, I never bought into the idea that God makes some people homosexual and God don't make junk so homosexuality must be good. So many unvoiced assumptions packed into that.