So, we try to avoid anger, and we often try to avoid even witnessing anger. This can escalate to the point of wanting to deny other people's anger - to tell them "you shouldn't be angry about that".
There is often a reluctance to baldly state: "yes, I accept the reality of your anger, I just consider the pain I caused that triggered your anger to be a necessary, or at least acceptable, evil". I don't know where that comes from - I suspect it's a desire to see ourselves as "nice people", so we're reluctant to admit when others may have a legitimate reason to be angry with us.
I suspect the only reason I manage to avoid that reaction in most cases is that I don't suffer from any illusions about being fundamentally nice - my core mode of operation is to do what I think is, on balance and overall, right, rather than what "won't make other people angry". Even though my concept of "right" includes "default to respecting others", it also sometimes means being the "bad guy" that decides who wins, and who loses in a particular situation. When that happens, the folks that "lose" have legitimate cause to be angry with me, and I need to own that and accept it as a consequence of my actions.