The problem with moralistic thinking is that it's stupid and it blows up, and we've known this for hundreds of years. What you view as moral means fuck-all. I don't particularly care if you think something is degenerate, and in fact by using a term like degenerate I respect you less as a person.
So when morals are used as the sole reason to justify law, we have a problem. Morals were used to justify slavery. To justify a lack of suffrage. To justify legal domestic abuse.
What's changed since then? Time. The passage of time. But time does not stop. Where will we be in 10 years, or 20? Progressing forward, ideally, but that's not a guarantee. We're laying the ground work for abuse.
For a large part of the American constituency, anything containing homosexuals is degenerate pornography. Right now. So if "it's pornography" is our justification, we have a problem.
I think we agree that said laws are bad, but why they're bad matters. The wider-scale implication is that moralistic law making is bad. Listening to Christians and having them come up with laws based on their personal beliefs is bad. Appealing to the American purity culture is bad. This is all ripe for abuse.