Partly for me it is that I would have expected a Windows 8 OS to be a lot more .NET centric. I think I even remember a Charles C9 video from years ago where he asks the windows server guys why .NET is not a part of server core, the implication being .NET is going to become more and more a part of windows. The message I was receiving from years of C9 videos was that .NET and multi core were it and naturally assumed Wiin32 and .NET would morph into 1 on future versions of the OS.
Really not complaining. I understand plans change. But I am a bit sceptical of the native guys saying in 2012 that we need every tick of the CPU clock we can get to run a responsive, power friendly app.