Their more-interesting projects would make a particularly-popular exhibition in an interactive museum. And that's about it.
e.g.
Why would someone want to spend more than 5 minutes on a 3D mapping phone? What would they do with 3D models, aside from playing Interior Decorator in their own living room or Hollywood Makeup Artist on their own face?
Those are neat ideas, don't get me wrong. But while more apps may eventually be found, it could hardly justify a specialized gadget for most people as-is. Particularly when traditional mobile device cameras are turning out inferior-but-quite-usable versions of those same apps.
Google Glass is similar. There's been a handful of really compelling use cases for HMDs for more than a decade. But the general public has never had more than about a 2-minute-demo-reel level of interest. And Google hasn't found/developed anything in Glass, yet, that changes things for people who already have a magical slab of glass in their pocket, everywhere they go.
(Google's actually dug a slightly deeper hole, in that people's 2-minutes-worth of interest in Glass was quickly dominated by how incredibly unsettling connected cameras can be, when they're potentially on anyone, anywhere. Including on the anti- and a-social, in places where people had traditionally let their guard down.)