As far as I'm concerned, it would hardly matter if the theaters charged $0 for movies.
My family almost always goes to the movies for a "family date night". Last night our concession stand bill was over $60, and that's just because I din't have a drink and we didn't get popcorn.
The theater we pretty much exclusively go to is one of those fancy places with the power recliners and food, so we will usually eat dinner there.
I know, this is choices we make when seeing a movie. But, I can't AFFORD to get unlimited movies for $10/month. :-)