I think that's part of it, but why do they think they are built that way? That's where I think we need to concentrate and attack (if I may). Science is no friend to the born that way theory. In fact, science is quite hostile to the born that way theory.
Those who push the born that way theory are completely ignorant of what science says.
They think they're built that way because they are TOLD that by people who tell them what they want to hear.
You're right...there is no "gay" gene. And if there were ANY group of people who have lobbied to try to PROVE the "gay" gene, it was this group. Science let them down--no "gay" gene.
I think they are like the sad sack women who hate themselves and want abortion to be legal and cheap. That is, those self-and-baby-haters will breed themselves out of existence and all left will be those men and women who WANT babies. Cosmic justice, A.K.A. The Creator speaks.
All we can do is repeat what Scripture and Apostolic Tradition tell us...and pray.