And I paid extra for this?
Doctors go to the movies, too.
Think about this: A doctor is on-call, meaning that at any moment they might be called in to come to the hospital to save your life.
They have a cell phone which is the only way they can be reached when they settle in to watch a film in the local multiplex. The same multiplex that jammed cell phones without telling anyone (because multiplexes hire idiots).
You come in to the hospital and need the doctor immediately. So they are called.
And the doctor's cell is dead.
And so are you.
(The ensuing lawsuit will totally bring you back to life.)
I know when I was on pager rotation, I was very aware of when I lost service, and governed my location accordingly.
Actually, I'm not on Internet Operations Pager Duty anymore, and I can _still_ tell you that the Old Spaghetti Factory in Redwood City results in my iPhone losing Data - I get very nervous while I'm there.
Net-Net - the doctor argument doesn't hold water, there are a ton of other reasons why you might lose service beyond a theater jamming - and you need to be aware of all of them and take appropriate measures.
In their main theatres they now have stroller screenings where the volume is reduced and the lights stay on low. They've done the sing-alongs. They also let you rent out the theatre to have xbox gaming with Halo or whatever you want to play.
Sadly the general theatres aren't great at policing the cellphones or no talking. Although I've heard several times that they're interested in the cellphone jamming, but it's illegal to jam 911. I have heard, and noticed, that in a lot of the newer theatres you get really poor reception in the general theatres. It could just be coincidence from them being out of the way and all the steel, but I do appreciate it nonetheless.