I don't understand what they are so salty about. In DD season 2 he did kill gangsters and etc but in his own series he only did it really in the first episode. Everybody he ends up killing is pretty either a black ops solider sent to kill him or a PMC solider sent to kill him.
It's very simple. One man standing up against those who would make him a victim is an acceptable narrative, but not if he wins.
If the person wins with his own skills and ingenuity against a powerful entity or, God forbid, the government, it makes people believe that they, too, can succeed on their own against injustice. No, justice is only had through the (self-)appointed champions who will go out, collect loads of donations, and then make a few token gestures toward changing the Patriarchal Hate Machine System before asking for another round of donations (don't ask where the first round went).
That is the Correct Method, and anything suggesting doing otherwise is badthink.