Honestly, I kinda take Gott Est Tot attitude towards the "classical" idea of completely privacy. Namely, times have already changed and that idea is not dying: It's dead. Gone. Lost. A decaying corpse from a bygone era. Changed completely by the modern era.
I can walk up to your face holding my phone and recording you, it'd be obvious I'm doing so and you can ask me to stop and I can say "no" and then you punch me in the face. With Glass, it's as obvious it's happening and the same things play out. Or it could be hacked to stop...and the hacker may as well have got one of those tiny super-effective cameras you can pick up for the same or cheaper a price than glass. That become a thing a long time ago.
And then there's the natural counterpoint. We saw it not that long ago in Turkey. Footage of the being instantly uploaded to a public internet from phones, this kind of technology does take away a government's ability to hide things from the world stage and serve to showcase what actually happens, exposing the good and bad and filling in pieces of the picture that would otherwise be missing.
As for the rudeness, people multitask all the time. Users have found it lets them pay more attention to things by making that multitasking easier. You'll naturally drop all things, including a phone/game/coursework/essay/book/other-thoughts for a serious conversation that matters, if people don't it's probably because the conversation is mundane enough to not need such a focus of attention. For a mundane conversation, which make up 99% of life's conversations, integrating other aspects of the multitask into vision whilst still allowing for eye contact lets them split attention more effectively and makes it less obvious. If anything, is it not less rude to allow them to deal with these things quickly and discretely as they come up, letting them dismiss what arrives and is less important than the conversation or immediately switch focus to something more important?
Here the madman fell silent and again regarded his listeners; and they too were silent and stared at him in astonishment. At last he threw his lantern to the ground, and it broke and went out. "I have come too early," he said then; "my time has not come yet. The tremendous event is still on its way, still travelling - it has not yet reached the ears of men. Lightning and thunder require time, the light of the stars requires time, deeds require time even after they are done, before they can be seen and heard. This deed is still more distant from them than the distant stars - and yet they have done it themselves."