It forecloses art as a career, thereby depriving future generations of evolution in style and professional craft.
I hate AI art too, but I don't think it's so bad as that. It's terrible because it uses obscene energy and steals art. But that doesn't mean anyone actually likes AI art (except people who make it and wish other people would like it).
If you tell me your "art" is AI, then I instantly lose interest (with very rare exceptions that generally use older types of AI, like MGMT's "When You Die" music video"). Momentarily disregarding economic considerations, AI "art" is to real art as over-processed food is to whole-food, made-with-love meals. Will some people eat it, for whatever reason? Sure. But are Twinkies competing with fine dining? No. I'm interested in art for the relatable human element. If that's emulated, then you can only hold my interest until that fact is revealed. AI artists can only be disinteresting or deceitful, there's no third option.
....Right, which is why the rest of that quote which you truncated for some reason was, "(except people who make it and wish other people would like it)"