@aredridel You're right that it's subjective, but I don't actually think that matters nearly as much as you seem to think.
When the model does this, the reason is it's literally pulling from training data that was acquired without consent or compensation of the authors. I know you know this; I'm just saying it to ground the conversation. I also know what the one Anthropic verdict said. As you note, the rest is unsettled and I remain of the opinion that a massive-scale theft occurred.
There is no author that is so naively pulling snippets of text they remember and putting them together like a ransom note. If they stray too far into imitation, there's a claim of plagiarism. If they lift whole ideas, same thing. And if they actually rip excerpts of text, well, I've failed students for varying degrees of that behavior depending on context.