Gays are secretly very scared of any discovery that the cause may be genetic. Because the next step, presumably, would be the abortion of babies who carry the gene.
Can't have that, can we?
Publicly gays prefer the cause to be genetic, because then they don't have to defend their choice. They also like to claim that being gay is common and that they are persecuted by straights. If all that is correct they will really have a problem in a generation once we've figured out how to fix broken genes. Let's take a look at that future. Instead of the current government mandated 20+ rare fixable diseases, newborns will be screened for a long list of dubious genes and their legal representatives offered corrective therapy. If being gay is that common and they are that hated then add it to the screening list and let those legal representatives decide whether or not to fix it. This decision can't be put off until the baby is an adult. Who would decide under current law? Parents, i.e. straight gay haters. It may not all happen at once, but evolutionary the gay gene will go the way of the dodo if you accept their premises. Look for them to push an "endangered sexuality law" to prohibit the testing and gene fixes.