Porn isn't art. That's an absurd thing to say. They have entirely different purposes.
The purpose of art is to create something of aesthetic value, in such a way that it can be recognized, reflected upon, and appreciated. Classically the aim was to create something beautiful, which would stir a feeling of sublimity. The precise aesthetic value aimed for has become looser in modern art. It could be something revolting the artist wishes to create, instead of beautiful. But the same intentional structure of recognition and appreciation of a representation of aesthetic value remains.
That simply is not the purpose of porn. The purpose of porn is excite the more base senses, i.e. to make the viewer horny. Aesthetic value in the artistic sense is irrelevant to the aim of porn. No reflection or mental appreciation is necessary or relevant for pornography to accomplish its designs. If the viewer gets sexually aroused and is motivated to watch more to self-stimulate, then the porn has been successful.
Of course, such absurd misinterpretations of porn that make it sound more dignified than it really is do help to maintain porn's mainstream, quasi-respected status and appeal. So it makes sense that the porn industry would promote this kind of nonsense.