> All this proves is that most people cannot tell if that picture is a Monet or not.

It goes beyond that. It proves that many people have an inherent bias against AI itself that's unrelated to whatever it generates. "This was made by AI, therefore it's bad in every way".

that's because when dealing with art, the "why" something was made can be as important as the "what"

... I mean, yes? People object to AI art (and generative AI in general) on ethical grounds, not just aesthetic ones. This is something anti-AI people are quite explicit about.