I'm loving (and developing in) VR, and interested in actual AR. Glass was a deadend as soon as I actually put one on.
I found it to be pretty much as if you were holding up a smartwatch beside one eye, that you could turn your eye and look at in focus.
There is no overlay of the real world. You are either looking at watch beside your eye or the real world.
The blurry screen was always kind of off to the side and annoying when wearing it.
Just as if holding a wristwatch up to the side of your head would be.
If that sounds bad to you, yes that's why it failed.