Brian Gleichman has written a series of critical blog articles on GNS/”Big Model” game theory, the first of which is here: Whitehall ParaIndustries: Flaws of GNS- Part I: The Appeal. Some of the commentary is both instructive and amusing as well.
I have to admit, a few years ago I was very interested in GNS. Over time, I tired of the elitism and almost religious fervor that emerged with regard to Ron Edwards (the author) of said theories. I still find game design that focuses on one of the GNS triangle corners to be an interesting idea, but firmly reject that this is the only way or even the best way of categorizing games or game-play.