The movie is not aiming for intellectual sophistication. It has a single, simple idea - to emotionally engage the audience in the relationship between the man and his young charge in the first half of the film, to exploit those emotions to drive the violent revenge fantasy in the second half, and to leave room for an audience-pleasing, redemptive ending. The direction was slick and the performances powerful. I thought it worked.
Liberal critics often object to vigilante movies - it might have found more favour if Denzil was torturing Republican politicians or Tories.