I recently had the experience of watching X-Men Origins: Wolverine. I went in to this movie with mixed feelings. On the one hand, some of my family had seen it and liked it. Also, the first 2 X-men were pretty good movies - not stellar, but good. On the other hand, the reviews were far from stellar. On the whole I'm glad I watched it. Not because it was good. It was, to me, the worst movie I've seen in at least a year. But I am glad I watched it because it helped me understand what makes a good comic book adaptation.
One of the challenges good comic book adaptations face, Batman Begins, Spiderman, Ironman (why all "man"s?) and so forth, is that their subject matter is inherently cheesy. A simplistic adaptation of any of these characters ends up with a guy in tights and a mask dropping insipid one liners while punching people. (Ok, Ironman wore a metal costume, but the same idea's there). What a good comic book adaptation does is take these characters and develop their back story, their context, and their powers (and their costumes) enough that you can engage with them as people. They'll never be "believable" but they are, (they do, after all, wear tights), but if this is done well they WILL be engaging. You can find enough humanity and story in there to put aside the men in tights aspect. To do this, the writer/director often must go beyond the original characters to some extent. Often not to a huge extent (Frank Miller's 2 Batman works - Batman Year 1 which became Batman Begins and Dark Knight, for example, both were well written and so translated well), but at least a bit.
The reason I came to understand this watching Wolverine is that they did exactly the opposite. They took a character who is inherently cheesy (the man has metal claws growing out of the back of his hands, and likes to growl, for Chrissakes) and they set up a story line that was if anything less believable, less engaging, and more cheesy than the comic book. They started with a nonsensical so-called plot (two mutant brothers are sucked into a mutant special forces that ends up hunting down other mutants all to develop a sinister super mutant who will hunt all other mutants, which Logan/Wolverine didn't know because he quit to become a lumberjack halfway through), threw in truly ridiculous dialog, and then went on to show that even competent actors cannot save a train wreck of a movie from itself. They did not do this to stay true to the comic book (I've seen that done - it turns into a train wreck too, but at least then it is a train wreck with a reason). No, they twisted the Marvel universe more than any of the movies I've mentioned above. Far more.
No, I think that this was the result of a different deliberate choice - not to make a bad movie, or a "accurate" movie, but to focus exclusively on bringing 1) a little bit of action, 2) a lot of special effects, and 3) as many good/bad guys with powers in as possible. All of this is done with no regard to any other part of the movie, parts like say plot, or character development. The bad news is that as a movie it failed utterly. The worse news is they made a lot of money at it, so we will of course see its ilk again.