> violence, incest, tribalism, and other undesirable evolutionary behaviors
None of the explicitly mentioned things in this list are similarly essential to the continuation of humans and human civilization. Like violence may in reality be unavoidable, but that doesn't mean it's strictly necessary.
But I do agree that appeal to nature alone isn't very strong. Like to me, I guess it's moreso what seems like extreme impracticality in trying to control people's sexuality to a finer degree than is already in place.