The tendancy to be an alcoholic is probably biolgical.
Does not mean being a drunk is no bad.
Also does not mean one cannot overcome a predisposition.
To steal your quote and change it a bit:
The tendancy to be a pedophile is probably biological.
Does not mean being a pedophile is not bad.
Also it does not mean one cannot overcome a predisposition.
http://content.gay.com/channels/news/heads/001117_gay_twins.html
There have been several studies of twins, at least one of whom is gay. In each case such as that above, in identical twins (obviously with identical DNA) the probability that the identical twin of a gay person was also gay was 50% or less. If there was a gay gene, the result would have to be 100%.