I'm always bothered when people boast that movies are never as good as the books. Working in a film retail & rental environment I hear it every week and my eyeballs hurt from rolling. These people come across with a pretentious megalomaniac sense of superiority that's really just an ignorant and self gratifying arrogance. A bit harsh? Yeah, I know but it frustrates me to no end.
I often doubt that these people have even read the books and it's more likely that they're riding the popularity train to Hipsterville. First and foremost a huge percentage of the movies we watch are based on novels that we've never heard of, and in most cases a huge amount of liberties have been taken by the filmmakers. This is because books and films are two entirely separate mediums... they might compliment each other but they're by no means the same.
When adapting a book the film maker has no obligation to stick to the source material verbatim and original text is often just an excellent foundation. Things that work in books don't always translate. An author is able to take as long as they please to explore characters and set up timelines. A book, in most cases, is as long as the author wants it to be whereas films are constrained by running times and audience attention spans. Alfred Hitchcock, for example, based most of his films on books, and it is universally agreed that he was a master of his craft... BUT I'm guessing that most audiences have never read the original novels, let alone heard of them. One of Hithcock's theories was that a film's length should be no longer than the human bladder's ability to hold. This is an idea that he practiced time and time again and most of us are grateful for that. We allowed him the creative license to manipulate his source material for the benefit of a great movie.
Haters be haters and there will always be wankers who bang on about book-to-film comparisons - but they miss the point. Books are beautiful things and they will always be there for us to get lost in, however, when an adaptation comes along it's important to judge it on it's own merits. Forget about the book and accept that changes will be made. If the film is bad, thats okay but recognise why changes were necessary. Stephen King will spend well over half of his novels with character development which requires in-depth exploration and psychological profiling. Books often get inside characters heads and approach storytelling from an angle that movies just cant access. Take The Shining, for example. Stanley Kubrick made all kinds of changes and removed most of the book's most fundamental themes. He also changed the ending, which worked so magnificently in the book but would have seemed ridiculous in the film (the TV remake proves this).
The Wizard of Oz, Mary Poppins, Lord of the Rings and 2001 A Space Odyssey are just a few examples that come to mind. All great and all granted creative licence for the sake of quality. Think about how much information a director can cram into an average of ninety minutes and form your judgement around how successfully the story was told using a different medium. With a more generous approach you might well enjoy more films.