I suspect it's often just the reality of the market. If theaters refuse to show films under an hour in length, every film will be at least an hour, even if a s

I suspect it's often just the reality of the market. If theaters refuse to show films under an hour in length, every film will be at least an hour, even if a shorter film would have been better. In a world where people go to bookstores to buy self help stuff, people who want to publish something about self help are going to have to write books.