you're missing the point in the article, this move will only be in effect in the more upmarket cinemas where the snooty posh people go who think popcorn is "ghastly and trashy" where the ticket prices arer double what any normal cinema would be.
it wont affect the usual, regular, down to earth cheap(yeah, right) and cheerful cinema chains. they realise they make so much money from popcorn, and that half the fat phuks wouldnt even come if they couldnt gorge themselves on popcorn.