Tradition vs. assembly-line storytelling
I found the Slate article very interesting, and nodded along with many of the specific examples of formulaic storytelling that were cited. This is not an entirely new phenomenon. Even in the days of oral storytelling and wandering theater troupes, there was a sense of expectation from audiences. They loved the classic tales, treasured myths, and bits of popular history; they had certain expectations of how a story would be told, and could become grumpy when those forms were not followed.
But it's so mass-produced now. Whatever else you can say about him, George Lucas made enduring magic with his relatively restrained budget, "Power of Myth" cheat sheet, and pile of images borrowed from classic swashbuckler and war films. One of the problems afflicting Hollywood is that everyone's really trying to remake "Star Wars" over and over again. And that's partly because blockbuster demographic targeting has required nearly every move to feature either Luke Skywalker or Han Solo as the main character. If every film is about a photogenic young male hero, there are only so many variations possible in the resulting story beats.
One of the beats they keep hitting that I find annoying is the "Chosen One" trope, in which it is revealed that the hero was born awesome. Even Spider-Man has been retconned to become a Chosen One. I can't help seeing this as a sop to the perceived laziness of youth culture. Hollywood thinks those precious adolescent (and adolescent-minded) moviegoers can't identify with a hero who goes through the wringer and perseveres by overcoming his limitations; they're flattering the fantasy of discovering that you were always destined for greatness, you were always meant to be a savior, You Are The One. And if the rest of the film has to be built around that, clock in with a brisk running time, and work in all the product placements and special effects money shots, there's not much room left for creative variation.