Here' my take on it, as another 20 year old.
There are definitely people out there like those you describe: the ones who read their horoscopes, shop online and perform any other kind of digital interaction in the wrong place at the wrong time and for far too long.
But looking back at the different people i met over the years, that category of people stays constant, and they are indeed the boring ones. Back in high school when the RAZR was the shit, these same people would be the ones constantly texting to people other than the ones they were hanging out with at the moment, and you'd have groups of people physically hanging out, but mentally they would all be focused elsewhere.
As long as that doesn't happen all the time, that's not a bad thing. What I've found to happen for the majority of people is that they still hang out and pay attention to one another, except sometimes they might quickly send a text or read an email. I don't mind this, and as long as you don't go overboard with it, I'm sure no one else minds. And yes you could argue that most things can wait for you to respond, but for the most part hanging out and maintaining a conversation with them does not require all my mental capacity, and part of it can easily be used for a one-off reply or message read.
Would most cases of Google Glasses be necessary for survival, or would they add that big of a bonus? Probably not. But even all those small things would be worth it. Like not missing that perfect moment for a photo, since the Glass would constantly record the past minute of your life and you could go back and get that moment in that footage. Even helping me figure out the names of people i've met before but forgot. One cool feature which for the msot part quite useless would be Google Goggles for Glasses. Scan my whole environment and tell me what you find. I'd have fun with that plenty.
And in my opinion the thing about all these worst case scenarios that people talk about, is that we have been led to believe by popular culture that they are more likely to happen than the best case or average case scenario. Think about it, almost every movie out there about the future has things going to shit, because those are more entertaining. A movie about humanity's first contact with aliens where everything works out and there's no war would be quite the boring movie for the masses.
As an aside, your name seemed familiar, and i checked my FB list of friends for you. Seems like you deleted your account, but I remembered that we worked together for HackNY, but You Probably Never Heard Of It. Glad you're doing well and congrats on the Codecademy internship.