If the all-you-can-eat subscription is run by the chains they might also be hoping to make back what they lose on ticket sales in concession sales.

Moviepass doesn't get any of that sweet concession stand money and they'd have a hard time convincing theaters that they should unless they start leveraging their user base (i.e. threatening to drop MoviePass from working at Cineplex) to pressure theaters. Even then they add so little value to the system that it'd be hard for them to do that while sustaining a competitive advantage against new market entrants.

MoviePass is just a terrible idea to be in as an independent business.