From what I understand in regard to the movie is something quite similar to what happened with the series. Universal put a lot of control stops in and the result was a movie that tried to be too many things, not b/c the content was not present, but b/c those who were controlling the purse did not have the same visions (a la Fox). Of course I am completely not objective in this regard ... well if such a claim can ever be true.
It is interesting to hear Joss talk in the extras on the Serenity DVD and then listen to what happened when he was involved with Aliens 3. It seems to me that vision and creativity are indeed a difficult thing to merge in a the medium of tv/movies. I feel that Firefly portends what that creativity might be - I also feel that the Firefly phenomenon (though akin to the Star Trek fan base) challenges a paradigm now with DVDs and secondary source sales challenging main stream channels (movie releases). It' an interesting world out there ...