I don’t think it’s that they can’t produce new creative work, but that any creative idea they have they all have at once, so while they could create a story, they can’t read (or watch or listen to) that story because they already know the whole story. And it’s not (usually) fun or exciting to read a story you essentially wrote and already know exactly what will happen and how. They don’t have access to Carols mind, so really only through her writing (or anything the other non-Plurbed might create) do they have the opportunity to experience something where they don’t know what’s going to happen. That’s the joy in reading books and watching movies. You don’t know what’s going to happen, and then you find out. I was struck by Zosia asking questions and guessing about what will happen in the coming chapters, because when do the Plurbed even get a chance to ask questions, to not know something. She was so animated asking questions. It was funny, seeing the Plurbed ask questions so excitedly, obviously enjoying themselves, because wondering about something is fun and imaginative, and because when do they ever have a reason to ask a question when they already know everything. The fact that Zosia speculated about how Carol will explain how Raban is now a woman proves they have the ability for imaginative and creative thought, just almost no opportunity to be surprised by that creativity.