I'm very curious what he means about the software not being right. I haven't played with the Meta Quest but my experience with HoloLens 2 is absolutely shit on the software side. Microsoft used to be decent at software (this is opinion but I quite liked Win32 and MFC back in their day). The HoloLens 2 software stack is just ridiculous on so many levels (they try to shoehorn Windows and Universal Apps, for the actual innovative 3D apps, you just use Unity or Unreal???). I could not believe my eyes when Microsoft's developer documentation tells me to use a different commercial entities software framework for 3D app development.

This is again a controversial point (but hey ... so is the letter being discussed) .. isn't the software framework for the 3D rendering, spatial awareness the future software platform (what Windows was or Android and iOS are today)???

I'm curious if this is the issue Carmack seems pissed about. Clearly there is a story here.