Even if we assume just for the sake of argument that homosexuality is a choice, so what? Surely it's nice if we have the ability to make our own choices in life? I can't think of a sensible reason why choosing to be gay would be worse. I really don't see how a reproduction argument makes any sense, if anything it's a favor in helping to slow down overpopulation or do you really want to see more and more population growth in the current world?