When Google Maps came out in 2004 and revolutionized mapping with the sheer quantity of data presented unbelievably smoothly, there was a similar (though smaller) excitment about "map-based" apps. It seemed like such a big blue ocean had opened and fortunes would be made on the back of new killer apps. I worked on a few prototypes myself and saw many pitches from various maps-based startups.
But pretty much only Yelp was able to succeed. There just aren't a lot of highly-monetizable applications that are primarily map-based. No one knew the limits at the time, though.
I think AR is in kind of the same place. The demos are mindblowing and there's enthusiasm, but there aren't a lot of killer apps with the state of the technology. For location-based apps, they really required a second piece in order to really open up the space: the smartphone. It may be that AR is waiting for some other supporting technologies before it becomes obviously laden with utility.