You could see the point, which makes you smarter than most folks out there.
Those of us who believe in God and the Bible recognize that morality is passed down from God but I often find that atheists, agnostics and libertarians refuse to recognize that fact, so I point out that even if you don't accept religious justification for morality, it still exists in a humanist form.
1) "Libertarian" is not a synonym for unbeliever.
2) In a sense, morality still exists whether a person chooses to accept it or not, since God still exists. But all the stuff I said still stands: you can't justify an "ought" within an atheist worldview. They rarely accept this in theory, and never in practice, because otherwise life is unlivable. For an atheist, a human as distinct from animal life is dependent on illusion. Only some of them really understand this.
I have to confess, I am confused now as to what your problem is with my original post. Was it the willingness to use a humanist argument? If so, that was because I detected (perhaps incorrectly) a lack of acceptance that morality comes from a higher authority.
Partly that.
You also seem to suppose that proving pornography is immoral means it should be prohibited. But this presupposes a great deal, that should be argued for rather than assumed, about the proper function of the government.