The problem with Watchmen (well, besides using a song other than Roy Orbison's version of "the Comedians" at the funeral scene), which I did enjoy, was that trying to jam everything into the movie that was in the book, simply because Snyder thought fanboys "demanded it," led to a rushed and disjointed movie in some spots.
For example: the Rorshach origin was shoehorned in. In the novel, you had an entire issue to develop the relationship between Kovacs and the psychologist. It had time to build to something and, as a result the doctor's realization, along with the audience's, of what had happened to the girl was horrifying. In the film, you had Rorschach stating "you can't get in my head, doctor" and then, thirty seconds later, giving the shrink--and us--a blow by blow of his encounter with the child killer and the dogs.