Google glass would work wonderful as a HUD in many applications, beyond just Military. Think of a doctor/nurse who could have stats in front of their eyes rather than on a cart behind them. Take it further and have it feed real time blood flow from an active scan, for where they are looking.
What is a Police officer, Bus driver, or other could have a camera showing whats behind the vehicle at all times, even when outside of it? How many times has a cop car been hit on the highway and the officer got lucky to survive? How about a security guard doing rounds of a building, he could get camera feeds or alarms sent to the HUD while out and about.
So the issue is not what they did or their idea, it was marketing it for the wrong places / application
The novels are much better than any of the shows, but even then, they still have those same campie moments. Star Trek is like a day time soap, in space... "Turn in this week to see who Diana Troy is dating".,...
Nobody said computers were going to be polite.