every “communist” when pushed will take position on atrocities committed by various communists regimes… they gonna do that thing that “fascists” do: “well he really did not do it but if he did, they clearly deserved it”

I have never encountered that argument. Is that something Tankies say?
What I have seen is the often mocked argument, that these regimes were not communist in the first place.
Actual communism has never existed and probably never will.
There are however plenty of communists that will openly denounce stalinism. That is the entire premise of Animal Farm, btw.