I've changed my mind about this a little bit recently: now I use it as a classier GoPro. There are a lot of times where it isn't appropriate to have a GoPro strapped to your head, but there's still good story potential. In most of those cases, the cool factor of Glass lets you get away with recording it.
My friends and I stitch the footage we collect from the adventures in our lives into a video every now and then, and Glass has added a lot to the storytelling capability.
Maybe wanting to record stuff makes me a narcissistic millennial, but it doesn't harm anyone and the videos we get out of it are awesome. I don't know if that use-case justifies Glass, but it definitely has some value for me, even if it's only used rarely.