I'm confused, does the BBC person not like Luther?
Granted, white Jewish person speaking here, one thing I always liked about Luther as a character is that he wasn't any type of racial stereotype or preconceived notions. There's dichotomy and conflict within Luther, along with contradictions.
Like on one hand, Luther is this very progressively minded intellectual. On the other, he seems to constantly shirk the rules and take brutal vigilante actions against criminals. Also, I don't condone the lengths Luther takes. He is corrupt and not free of guilt. I simply think he's been on the job so long, it's de-sensitized him, so he has difficulty empathizing with criminals or murderers he knows have done wrong.