has-been tough guy Denzel is out for revenge, but why?

Rating: 8/10 (7 May 2005)

I think the ending was very good, nice for once that the two main characters do not fall instantly in love and live happily ever after.
I think the movie was very as such was good, however I am not really convinced by the plot. I don't understand why Denzel would get so attached to the little girl and v.v. At not so attached that it would make killing everyone involved into the sole meaning of his life.
I know it is explained that he was an ex combat/hit-man whose life took a nice turn through the friendship with the girl, but it is a little bit too weak a motive in my opinion.
It is also not very easy to picture a man like Denzel Washington as a drunk. His whole stature and charisma implies discipline and control.