Pass-through VR headsets will never, ever meet the use cases I have in mind, like integrated virtual HUDs for pilots or machinery operators, or even construction workers on large building sites. Going blind due an equipment failure while operating tons of moving machinery is not a reasonable failure mode.

And speaking personally, I just don't want to be disconnected from the environment in which I am presently existing. Projected overlays on glasses could be useful, I'll grant, but not a vision-restricting, self-isolating VR headset.