A stupid hail-mary from artists who are quickly seeing their industry changed by new technology and want to stop it rather than try to adapt.
AI art is here, and it's not going to go away. It's way too convenient. Why pay an artist to produce 2-3 mockups in a week when you can use AI to produce dozens of completed pieces in a few minutes?
The arguments of "they're using human made art to train without permission!" are short sighted and born from desperation. What do you think an actual human artist does when learning to create art? Do you think they work in a vacuum, or do they take inspiration from other artists?
If you think it's different because AI is involved, then let's take this a bit further. For the purpose of this metaphor, let's say someone wanted to make an AI that could produce art similar to Dr. Seuss, but all Dr. Seuss artwork was banned from being used in AI training. What is to stop an AI company from simply hiring a bunch of cheap artists from China or India to produce hundreds/thousands of images in the same style as Dr. Seuss and using those to train the AI? You can't copyright a style. If other humans are free to take inspiration from artists and produce work in a similar style, then AI is too.