Apocalypse World exists because I took a good, long, non-nostalgic but backward look at good GMing.
Sure – it has us prepare fields of potential threats, rather than forking paths, and react interestingly to player's moves/decisions rather than defensively.
I think the SG crowd is still dealing with the desacralization of the GMing mystique. Once you break it down into a series of discrete tasks, it exposes the wizard behind the curtain (the GM behind the screen, if you will).
BUT what such a breakdown actually does for some is to challenge them to either rise to the task of becoming a "good" MC or
or actually codify what their version of a good GM would be in opposition. Either responses productively reflects on the discourse lurking behind the reams of guru-toned prose on "How to Be a Good GM" of Kevin Siembieda, Robin Laws, Gary Gygax and all the rest.
understand the GM as just another part of any dynamic system we call an RPG, but such an understanding also forces us into brave new territories of negotiated play that may be closer to my ideal in any case.