I never said there aren't any reasons it could hurt the community. I simply asked what those reasons might be, and you have given me an answer to my question.

My counterpoint would be that it's also possible that the increased activity from the AI art community energizes and grows Lemmy as a whole, and some of those users are also interested in other art.

I think that your beef is with AI art as a concept, not with the Lemmy community in particular. I feel terrible for artists that are losing their livelihood due to AI, but if AI is going to affect my life going forward, I would like to understand how it works and how to deal with it. Observing that Lemmy community has helped to clarify the capabilities and limitations of AI for me personally, along with providing entertainment.

TLDR verifiable pros > hypothetical cons