You'd rather a politely worded letter to the artist's local newspaper?

Meh, not entirely sure what would work better. Having read through the huggingface post a few times now, suppose it's less of an emotional reaction, more actual protest to abusive practices.

I'd rather they do... art?

Why not organize a worldwide protest where every participant produces and shares Art denouncing generative AI? "AI might produce single pieces but this collective work, this is what AI can't do" and so on.

What they're doing is so weird and ineffective in contrast, it baffles me.