One *could* argue that the way Anthropic used training materials is more analogous to a budding professional musician learning from, and being influenced by music they heard on the radio to develop their own "product"...arguably different than openly redistributing copyrighted material as-is. It's definitely uncharted territory though.
Of course you're right that things like fair-use provisions and software/content licensing never saw these models coming, and the inertia behind them means that future laws/rulings are unlikely to significantly roll them back. It's also a certainty that the creators of much of what ended up being training materials never intended for their works to be used that way.
So ya...ethically questionable origins? Yes. Useful when used responsibly? Also yes. Potentially harmful when used irresponsibly? Of course.
