Each piece of hardware tied to its single use/single content company
With the AR sets in particular, each piece of equipment seems to have been dependent upon one company for both the hardware and the (limited) software, the latter in particular being locked-down and limited in use. When that one company loses interest in the device both hardware and application become defunct. The hardware wasn't compatible with any other manufacturer's, assuming that at that time there actually is another manufacturer making anything similar enough to be usable.
Since the 1990s I tried to find (what we now call) AR displays. After all, a working one had been shown on Tomorrow's World (IIRC basically an endoscope cable attached to one arm of the glasses, reflecting off a semi-silvered patch on the inside of the lens; mostly analogue), an affordable product must be available soon!
My niche use-case was simple enough: I always wanted to be able to VNC into my desktop so that I could use the s/w tools I'd setup just the way I like whenever I was watching over a colleague's shoulder; I'd even got a funky one-handed chording keyboard to learn. No more "just search for alpha charlie - no, just type a then c, no, I didn't say put a space between them, here, let me type - gaah, why do you have that key mapped to delete paragraph? What do you mean, you don't have grep, there is a Windows exe on the share you were told to add into PATH". Or during a meeting, discreetly look up the email (I know where *my* copy of it was stashed) without crouching over a laptop (when they actually became usable as a desktop replacement) or, these days, squinting at a 'phone, but instead at least looking like I was paying attention to the presentation.
Over the years, there have been plenty of products that could have made that possible (there is a list somewhere in my notes, now mainly a list of defunct URLs) but either they were pricey-but-I-could-manage-it gadgets whose maker vanished almost as soon as someone could publish a review or they were insanely priced along with the only software package that could drive them, usually medical or military. And those never seemed to last much more than a year either (the URLs certainly didn't), no idea if they ever made any sales.
More recently, we had Google Glass (sneaky camera, data slurping and stop making the damn display run an entire Android stack with Alexa/Siri/Cortana/whatever added in, I just want a peripheral display) or Hololens (yes, lovely AI driven API or whatever, not interested, gimme a basic peripheral) or even a slew of Kickstarters (only talks to their iPhone app and/or focussed to appear 10 inches in front of you).
Fantasy time: how about a few manufacturers making wearable display peripherals with a common interface and a variety of form factors (semi-silvered specs or dangling mirror on a headset - Ketracel White optional - or Virtual Light for the adventurous). Then have Google strap a camera to it, MS can flog you a subscription to their cloud API for the Holoadaptor, Gucci et al can put a logo on it, Swarovski can bejewel it. People with their own niche ideas can try them out whilst others just avoid tired arms from holding their phones up all day long.
Maybe then there is a chance for economies of scale to kick in for the displays, technical competition and improvements in resolution without chucking everything out and starting from scratch again.
And I can connect it to a minimalist VNC client and be quite happy in my own little world (except that I've forgotten the keyboard chords, dang).
