It's all about the story and characters, not the medium. I'm more of a film fan myself, but usually the book is better than the film.
The book is more detailed and most everyone wants to spend more time with characters they love or places they see. The book almost always gives more of that than the movie. It's a legitimate reason, an advantage of the book medium and not something that should be dismissed.
Another reason books tend to better is that allow for more imagination. With a book you are the director, you cast all the characters, design all the places, and choose the shots. A movie will rarely ever match someones imagination. So when a book is adapted, and it's not like what a reader thought, it's disappointing.
Where book adaptations fail is when they try to condense the story rather than adapt it. As you have pointed out they are different mediums and one can't expect that a script hitting on the plot points and having all the characters from the book to automatically be good. It needs to worked on, and seriously though about. Often this does not happen and we get poor adaptations.
There are plenty of films that are better than book. The Godfather is a better film (especially when taken with part 2) than the book. Fight Club is at least as good as the book, the author even prefers the film ending. Just recently Coraline was a great adaptation.
In the end, I don't see why one can't enjoy both. You seem hypocritical in your assessment because you dismiss books just as easily as those you criticize for dismissing movies.