I think there is some sort of evolutionary programming to reject homosexuality. The reaction is so visceral, it just has to be. It is reinforced by millenia of social programming, with some variations depending on the society. (look at ancient Greece) Trans people are lumped in there by social construct however, I think. After all, were there trans cavemen? Possibly there were, they just wanted a different role? Maybe it was even acceptable.
But, are we not beings of reason? I hope so.
