We're used to a story in modern terms as an information delivery device. Certainly on television and even with the studio films, there's really only one note that you get, and that's clarity. And people will sacrifice everything for clarity. They'll sacrifice the joke. They'll sacrifice the moment, or the romance.
What's great is that each medium has a unique set of things that it does and does well. Film is a visual medium, and obviously, you can't fit a whole book into two hours unless you're really economical about it. Obviously, they say a picture is worth a thousand words, and on some level, it's sort of true.