For example, I don't think Sarah Andersen, one of the plaintiffs here, would've reached the popularity she's gained now if it wasn't for her comics being shared on meme sites and social media, for example, and I don't see any "do not repost" watermarks on her recent work like others that do object to resharing on other platforms have started doing.
I think many artists and copyleft programmers have the same positions. The biggest difference is that drawings are considered "art" and code is generally not, despite that fact a technical drawing and business logic are both hardly artistic and mostly an expression of skill whereas the demo scene, the indie gaming scene, and many online artists are very much about expressing themselves within a given set of boundaries.
When Microsoft steals code licensed to Github, people considered that to be a license dispute more than a copyright dispute. I'd argue there is no difference at all between artists and programmers when it comes to their work being absorbed and then reproduced by an AI company.