I would like to extend this to smart watches. So many conversations I have had where someone is constantly glancing at their watch. I know it is just an automatic response to some vibration but sometimes it feels rude.
It is rude, and exacerbated by smart watches; just not unique to them.
Possibly, though my intuition is the opposite. I don't think social norms are "fundamental" in a strict sense. They're just important. That said, the reasons not to jump in the deep end is because it makes fundamental-unsovlvable problems indistinguishable from advanced problems that will be solvable later.
IE, if someone is using smart glasses for work or some other activity where they are useful, they might expand their use into other activities.
You could not have invented Tinder or snapchat in 1994. User density, camera, ubiquity, and other hardware issues matter. Besides technical issuaes, culture also had to develop before people felt comfortable using real names, posting pics and meeting people from online. If everyone already posts on facebook, the world may be ready for online dating, online therapy, etc.
While I do agree with the general point about not judging experimental devices too harshly you're making an assumption there that there is an application for general purpose, wearable smart glasses.
I'm really skeptical. I did some work with Google Glass back in the day and irrespective of the way it looked it was really socially jarring. You could be in a conversation with someone and see their eye drift upwards to read whatever notification arrived on their device. It felt rude. At the same time who can blame them for looking at the flickering message an inch from their eye? Snapchat sunglasses felt socially jarring in a different way: whenever you were wearing them you were constantly pointing a camera at someone.
There's something very fundamental to the nature of these things that makes me feel like they just don't work. I can see them being incredibly useful in professional contexts (IIRC there were trials with giving Google Glass to surgeons, makes a ton of sense) but as a general thing we're all going to be wandering around with strapped to our faces? I dunno.