If you expect every movie to be exactly identical to the book, firstly, there are several movies (Harry Pottter, The Lord of The Rings, and Twilight to name a few) that would be hours upon hours long. Harry Potter is already a three hour long movie for each installment of the series.
Secondly, it would be pointless to even publish the book.
Reading books is all about using your imagination.
The writer might as well go straight to a movie producer if it's going to be that big because most of the time, people wait until it's out in the theatres or on dvd to find out what it's all about.
Cutting things out is what makes those people want to see what things did or didn't make it to the movie so they read the books.
YOU ARE READING
Random Thoughts
Contothought /THôt/ (noun) : an idea or opinion produced by thinking or occurring suddenly in the mind