Think about initial smartphone adoption. You could've argued that they provided little benefit over a laptop for many features. The displays were small with low resolution, web connectivity was slow, websites weren't optimized for mobile, and the cameras were pieces of rubber duckies. But they were cool, and people found a use for them as technology improved. As techies, we should absolutely not be dismissing first-generation tech.
Yes, voice control is freaking awkward, but there are solutions to that. Thalmic Labs, for example, is coming out with the MYO (go watch the video) which would be perfect for interacting with Google Glass. Make a hand gesture to take a picture, instead of taking out your phone and positioning it? Seems like a natural fit to me.
I'm guessing Google Glass will converge around the $400-$700 price range, possibly with more than one model. Youth adoption will probably drive overall consumer adoption. As with a lot of new stuff like this, it's easy to say you don't need it. It's harder to say you don't want it after you have it.
I have a feeling you may be right in the long term that Glass may prove successful, but I just don't see anything like the same benefits. My smart phone gave me fundamentally new capabilities. Glass seems to just make them more convenient.