I disagree that 90hz is a problem, given that I've played games with varying limited frame rates on my DK2 I can say this is less of an immersion breaker for me pesonally than physically being able to see each pixel.
I think what you're saying is hyperbolic given that most average users strive for at least 1080p in their gaming monitors and that's for a relatively tiny FOV of whatever their monitor in their field of vision is, maybe ~30 or so degrees, vs the ~90 of VR.
One of the best sites that demonstrates this is here -
http://vr.mkeblx.net/oculus-sim/ select the 1080p panel and you basically have pretty close to the Oculus CV1 or Vive as they are right now. 2560x1440 is a big improvement but 4k is really what we should be aiming for as a standard. And with Nvidias new technology to render VR faster with the 1080 range of cards and also make resolution compromises for parts of the lens that are most warped it really reduces the overhead of trying to power 4k as well, so we're really ready for it.
The fact that Oculus got the insane investment they did but they couldn't actually get custom built panels for their product is mind blowing to me, they just tried to cut corners and missed their launch targets which was originally to be higher than 1080p