I thought this was handled well in this piece in the New Yorker, where the writer said:
“Any novel can be the basis for a good movie, if the filmmakers only dare to betray the book—to treat whatever interested them about it as raw material that they’d approach as freely as the authors had done when writing.”
Even writers who create an outline before starting writing have the ability to go in a different direction at any point when they actually start writing the first draft.
And I liked this phrase also:
“… the mechanical tone of a cinematic Pez dispenser proffering sweetened and uniformly shaped lozenges of incident.”
This reminded me of both the movie of Inherent Vice, and every movie adaptation of Henry James that I’ve ever seen (and I’ve seen quite a few, for some reason). Sometimes portraying the events of a book (and usually only selected events at that) is nothing to do with telling the story that the book tells.
On a completely different topic, I liked this article: “The Debt That All Cartoonists Owe to ‘Peanuts’“
And this one: “All I Ever Wanted Was a One-Trick Pony“