If the same amount of tickets sold, yes, a 15 minute movie would be preferable to a 2 hour movie (from a theater owner point of view). Now, of course, most people aren't going to spend full ticket price for a 15 minute movie. But would they spend full ticket price on a 90 minute movie, made for kids, when they know their kid can't sit still for a full two hours, and they (the parent) don't want to be in the theater for two hours? Would even more people pay full ticket price for a childrens movie with the shorter runtime? Those are the relevant questions.