Too Smart for its Market
The main reason why this film has received so many poor reviews and low rankings on this site is that it simply did not meet the expectations of the people to whom it was marketed.
This is a thoughtful film... a film that cares more about its characters than flashy, choreographed fight scenes. The problem is that the type of person who went to see this movie isn't looking to think, but to be mesmerized by flashy fighting, of which this film has almost none.
This is a movie about relationships, believe it or not. Unfortunately, it was marketed to 14-27 year-old men, who couldn't give a damn.