In the era of reifying "exposure" and lots of friction in donations, they're worried that machine learning-based image generators would overwhelm the feeds and suppress their reach. This is a problem created by lack of transparency in the social silos and the friction of fiat money.
In the era of social network silos being dead and the #zap mechanism on Nostr flourishing, they really have nothing to worry about. As long as they still got some rich patrons who will zap them and commission arts from them.
I would personally love to commission an artwork from a human artist — but due to me being cut off from the greater fiat financial system, I lack the pathways to do so — even though I have the money.