Fair enough.
I dislike it because it used the name of a book which had a much more creative and compelling ending, so comparably the one they released in theaters was pretty terrible.
As I said elsewhere, it's like changing the ending of 300 so Zeus comes down from the heavens and destroys the Persians with lightning bolts, saving the Spartans. Sure, it might be a cool scene (if done well), but it wouldn't be as good of an ending. And, almost as importantly, it wouldn't fit the first 3/4 of the movie.