I think it was very much an adaptation for the fans, like the exact opposite of LXG or Schumacher's Bat-nipples. The best ones are the adaptations that reach a ballance, like DKR or Iron Man.
I think as a fan though you'd like to see something new fleshed out of the material, I know I do. Though I'd rather see an exact adaptation like this than Elektra or Shumacher's take.
This may be heretical, but actually think the movie would have improved with a little less faithfulness in a few places, especially when it came to Rorschach.
While it was fun watching him kill a Pete Townsend lookalike, the whole bit with the shrink and the origin felt shoehorned in because they assumed that "the fans" needed to have it. In the book that was true. In the movie, however, I think it was sufficient to just note that Rorschach had kept working while the others had quit and show that he had clearly gone insane. We've all seen enough movies like "Taxi Driver" and "Lethal Weapon" that we could fill in enough of the blanks to know what motivated him.
Furthermore, in the book, the bigger point of the origin was how working with Rorschach over an extended period of time began to affect the doctor and how the reveal was built up to slowly. In the movie, it was "well, I've faked you out with references to butterflies and flowers for about five minutes, and now...because the fans demanded it...I'm going to tell you about the dead dogs and the child molester I murdered."
I would've rather they spent that time fixing some of the rushed details of the ending.
