We don't all live on Elysium.

Um, no I don't.  I can't afford a smartphone.  Maybe someday.

I may or may not be under the age of 21 and I only use my phone for texting, the odd phone call, and as an alarm clock. I have other devices to satisfy most other technological needs.

Doesn't help that almost every smartphone I've used has awful call-quality and is shitty as a cell-phone.
Those $20 Go-phones you can buy at any convenience store beat the shit out of an i-phone when it comes to actually, you know, calling up and talking to human beings, instead of updating your twitter feed.

That being said, I do use my phone a lot to check email and the like, but not super often, and I certainly wouldn't look down on people for not trying to be connected every waking fucking moment

Some people just have no concept of phone etiquette. I also don't believe it has anything to do with having a "right to be connected", it's selfishness, either knowing or oblivious.

The best solution is embarassment. Switch off the film, turn up the lights, and have an usher walk up to the perpetrator and ask them to stop, then resume the film only when they've stopped. I bet that person wouldn't ever do it again. Because clearly, others have let them carry on with being a selfish arsehole for much of their life already.

In Britain, they have "Quiet" carriages on National Rail, and the big shitstorm is that everyone ignores that and carries on talking, telling their frigg'n life stories on the phone and to everyone on the carriage.

So, likewise, you can have cinema screenings designated 'QUIET' but until an enforcement policy is decided on that doesn't infringe civil liberties, it's going to be ignored by the 5% of assholes that spoil it for everyone else.

Cinemas need to decide which side their bread is buttered on.