This has some interest for the big screen aspect. Think about it, a high end Apple display can run $5k for only 32", but you still have to leave it at home/office. With this setup you can take your display(s) with you, whether that's on the airplane, train, hotel room, or just your bedroom. $3000 is for the bleeding edge early adopters, manufacturing, and corporate customers. In a few years it will be a more acceptable $1k, still hefty, but acceptable versus the cost of a display these days. Plus there are other benefits, complete privacy for your screens, and all the functionality AR and VR bring.
I think the mistake being made is to think these are going to be worn walking down the street. Maybe someday, but I don't think in this iteration at all. My only gripe is if they are going to dumb it down with iOS and make it "iPhone and iPad like," bleh. I hope they make the sum greater than its parts, like Samsung does with Dex.