I think the issue is that its actually quite difficult to "unlearn" something once you've seen it. I'm speaking more from human-learning rather than AI-learning, but since AI is inspired by our view on nature, it will have similar qualities. If I see something that inspires, regardless of if I paid for that, I may not even know what specifically inspired me. If I sit on a park bench and an idea comes to me, it could come from a number of things - the bench, park, weather, what movie I watched last night, stuff on the wall of a restaurant while I was eating there, etc.

While humans don't have encyclopedic memories, our brain connects a few dots to make a thought. If I say "Luke, I am your father", it doesn't matter that isn't even the line is wrong, anyone that's seen Star Wars knows what I'm quoting. I may not be profiting from using that line, but that doesn't stop Star Wars from inspiring other elements of my life.

I do agree that copyright law is complicated and AI is going to create even more complexity as we navigate this growth. I don't have a solution on that front, just a recognition that AI is doing what humans do, only more precisely.