You mean selling porn, or making porn?
Making porn, compared to a prostitute having sex with a john, yeah, it's the same act, getting paid to have sex.
Don't know, maybe you can pass off porn as a form of art, and that somehow makes it acceptable.
If I was filming a murder, the murderer would still be liable. Doesn't matter if the filming was art or not. In fact, people would be screaming for the person documenting to be tried for a crime as well.