Earlier quoted context omitted.
If it's known that the theatre is a phone dead zone, you can step outside the theatre and make the call. If someone's having a heart attack, you have a whole theatre full of people that you can pull resources from. A car driving around is a secret dead zone that punishes you for being nearby, even if you're not transgressing any social norms or traffic laws. Sitting on a park bench nearby? Hell, even being a passenge…
I think the point was that if a theatre installed jammers, then patrons could not receive calls. Yea, I get that no one wants to overhear someone having a long chat with their significant other right as the plot line thickens, but a doctor on call or a parent who's kid is just got hurt at the baby sitter might appreciate being able to receive a call or text while their phone is on silent. They can then step out of th…
As for the babysitter, deal with it. If you're not contactable for 90 minutes, you're not contactable for 90 minutes. This perma-connectivity is an entirely new phenomenon, and there's no absolute need for it. Essentially this argument is saying that the parent's inability to deal with lack of connectivity is a convenience which trumps the general theatre-going public's convenience of not having people talking on the phone, or who light up the people behind them because they're bored with the movie and are playing online.
Being uncontactable for a short period is not the horror that it's made out to be in these arguments. The good old argument that someone can't sit through a lecture without connectivity "in case Auntie Mabel dies", but of course it's just a cover for having phone access for other things. If one were to believe the excuses that get trotted out, you'd be forgiven for thinking that human mortality had skyrocketed since the public acceptance of mobile phones :)