The issue with VR is that it almost entirely doesn't require his type of expertise for it to succeed. It's almost entirely a hardware problem, in terms of cost, wearability/usability, quality, along with the other issues like nausea etc. None of which Carmack's vast expertise lends itself towards. Writing an app for Netflix isn't exactly using his skills.

We see this often with engineering types, many of us included. Vastly underestimating difficulty of challenging problems and naively believe they're simple to solve.