Multiplayer VR(and not just games, but general social interactive experiences) could be totally revolutionary. This doesn't have to be some antisocial medium that's only suitable for playing in a dark basement or something. And its perfectly possible that there will be ways to switch back to what's around you if necessary. Like having a little camera that can instantly project 'reality' onto the screen for you.The main problem wasn't the size or price of the system. It is an apt comparison because the main problems remain: You need special hardware, you're alone, and you waste insane amounts of processing power computing shit you'll never see. And those are systemic issues.
Special hardware, ok maybe not solvable per say, but hardly some impassable roadblock. If the experience is good enough, it will be worth buying the hardware.
And I don't know why you're talking about 'wasted' processing power. Its going towards creating the virtual reality for you! That's possibly one of the best uses of processing power I could imagine not related to science and research.
This aint your granddaddy's VR.