It's an interesting thesis but I think it bakes in so many assumptions about how the players are approaching the game already as to not be generalizeable to D&D. It works if you image that RPGs are about improvisational storytelling first, and then you want to layer on some rules. But it's just as easy to imagine the opposite--they're a game with rules first, like a wargame or chess. And then you decide to give the players more flexibility, and there is ambiguity in resolution, so you introduce a referee. In this case it's clear that the characters are game pieces first, and you're personifying them after. With that approach, saying the character sheet has nothing to do with the character misses the point.