Anyways, that doesn't have any impact on other people doing the phone thing. It's a lot easier to not be nose-deep in your phone when other people are engaging with you. I find that most people settle into the "trance" based on whether other people are on their phones. The people who start the "trance" are often preoccupied or just plain rude.
Another facet to this is that we just don't know where this is going. Is it a step forwards or backwards. Hard to say that it looks like a good thing, but many of us didn't grow up with it - what will the story be like in 50 years? None of us has a clue, to be honest.
Anyways, I think what it comes down to is the "responsible use" cliche. There are so many constructive things you can do with technology. But here we all are, reading these comments which don't matter and are just random people screaming into the void. Shit.