In a post-scarcity solarpunk future, I could imagine some reasonable uses, but that’s not the world we’re living in yet.
AI art has already poisoned the creative environment. I commissioned an artist for my latest solarpunk novel, and they used AI without telling me. I had to scrap that illustration. Then the next person I tried to hire claimed they could do the work without AI but in fact they could not.
All that is to say, fuck generative AI and fuck capitalism!
What makes you sure it's a grassroots movement? The harassment I've gotten for sharing stuff generated from AI horde leads me to believe Fuck_AI and similar spaces might be filled with Astroturfing trolls. When they lie and use extortion to try to silence their opposition that leads me to believe they aren't credible.