First off, it isn't a mob movie. Second off, action? If DeNiro actually shot that gun would it have been better? Third, you didn't like DeNiro character. You weren't supposed to! He was a street punk, DeNiro doesn't have to play likeable people. And final, as I said it isn't a mob movie, it's a personal movie about the life Scorsese knew very well, and he blends religious guilt, his style, and a good plot together magnificently. The direction is superb, and out of all of Scorsese's movies, it has the best soundtrack.

That's why I think it's a masterpiece.