I had a (very) small part in it -- in 2001, I was chatting with Caterina, and recommended the book "Finite and Infinite Games" by James Carse. She then recommended it to Stewart, who found in it at least one of his inspirations for GNE.
I appreciated it for giving a clearly articulated alternative to zero sum competitive games. It helped me think about the playfulness of cooperative creativity in a new more holistic way, as well as the idea that it’s worth doing things that you’ll never reach an end of.
I don’t doubt that if I read it again I’d share your criticisms though, it’s a thin volume with a very sweet idea at the core of it, at the end of the day.