Not really surprising. The surge of pre-orders was simply a very small number of enthusiasts jumping in on the "10-20min tech demo to show off to your friends" thing. Once that backlog of orders was cleared, it was pretty obvious $800 "mainstream" isn't happening (for the same reason the average consumer doesn't buy $800 monitors to plug into SLI'd Titan's).
have you ever used vr at all?
I tested a friend's out and while it "technically" worked, it's something I couldn't use for more than 30mins at a time. Compare that to the up to 14hrs I can easily sit in front of my flicker-free 27" IPS with comfy Sennheiser's. Even if they sort out the motion sickness / Vergence-Accommodation Conflict / nausea / spectacle wearer pressure / unit slips if you move too much etc, issues, other discomfort issues remain due to the nature of the technology. ie, if you stick something over your eyes that creates a "seal" that blocks out light, over time it's also going to trap a layer of warm air inside causing hot / dry / tired eyes. A LOT of people are complaining about this without any real resolution, and even the Techspot VR reviewer Kirk
wrote "It gets warmer over time, as well, and after playing for an hour or so I’m acutely aware of the fact that I have a heat-radiating piece of electronic gear strapped to my face."
VR ergonomics are nowhere near as natural or relaxed as simply flopping out in front of a 2D TV / monitor, and I doubt they ever will be due to the nature of sticking a heat-radiating, light-tight, heat-trap over your eyeballs...