Well thought out and sensible position overall

> It's actually an extremely consistent worldview.

A consistent worldview but not a consistent argument. It's possible that those people are just wording their argument extremely poorly.

It would make sense if they argued that theft in one direction is sometimes justified, if they argued that allowing AI companies but not individuals to infringe copyright is a double standard, or if they argued that copyright should not exist but that copyright laws are at least a way to reign in the harm caused by AI training, but I can't see any consistency between "copyright is a legal fiction that should not exist and copying data is never theft" and "AI companies are stealing because they're infringing copyright".