I'm sorry. I assumed you knew at least something of which you spoke.
"Cell" communications are for pagers, business devices, emergency devices, computers and just plain phones. The idea that some dolt could flip a switch and throw out the baby with the bathwater is dangerous. I could give a care less about your immature customers who are so ill-mannered that they would take a call in the middle of a movie. Police that. Don't cut off a lifeline to the rest of the planet because you are too damned afraid to straighten a patron out for the sake of the rest of your patrons.
I'm sorry too: I thought this was civilized discourse. If I want to block all RF of every kind on my private property, I should be free to do so. If I want to make a house rule that all males squat on their heels instead of using chairs, I can. It would be bad for business, but that's my problem. I should be equally free to ban bald people, and to mandate that everyone wear a T-Shirt saying, "I'm with stupid." Why are you confused what private property means?
You must feel that you are the only person who matters. If a theater owner does not want cell phones in his theater that should be his business. If you do not like his rules go somewhere else. Stop trying to force everyone else to conform to your wants.