Joe Posnanski describes a certain kind of Hollywood plot:
How many movies would you say you KNEW the ending before it happened? I'm not talking about you figuring out the ending of Sixth Sense or Usual Suspects or Memento or whatever (good for you, Nostradamus). No, I'm talking about movies that are essentially made with the premise that you will know the ending. You know the killer will die. You know the guy and girl will get together. You know the planet will be saved. You know the home team will win. You know George Clooney will end up in a tuxedo. You know the castaways will not get off the island.
You know because you are supposed to know, the director expects you to know, the producer expects you to know, the actors essentially act like you know ... KNOWING is part of the experience. This is why sometimes you will hear people, when asked about a movie, say something like: "Oh, well, it was predictable, but it was still pretty good." There is in some of us a capacity to not only like a predictable movie, but like it BECAUSE it's predictable.