I'm quite sceptical about the short-term prospects for this, although I'm actually more open to the idea of this being a media consumption device.
However, the fundamental problem is that I don't think Apple has shown a use case that would justify the price, although one might of course emerge later, nor does it have a product at a price point for the use cases it has shown.
I could see myself watching an immersive movie or playing a game on this, but I'd probably need at least two so I could share the experience with my wife, and I'm absolutely not prepared to spend $3.5k for that. Combine that with the fact that, at least initially, they'll probably struggle to get people to produce content that actually takes advantage of the glasses for a minuscule number of people and it seems less appealing.
Again, the use case may not be immediately obvious. Maybe we'll look back in a couple of years and discuss how their success is so incredibly obvious in hindsight. Maybe, but not necessarily by a long shot.