I'm not suggesting abandoning the intention of being the good guy. Instead, I suggest to stop using it as a shield or plausibility cover for misdeeds. Instead I suggest the viewpoint of "Hey, we're trying to be good, but we fail sometimes. Let's accept it and collectively try to construct a better good, which is fair and equal to everyone, as much as possible." I think this is workable and can be iterated upon to make a better world (I know it's very hard, but it's not impossible).
Morality and ethics is universal. They're hugely important values to build upon, but interpreting them according to one's desires or in a subjective light, without empathy, makes them hollow. Again, a lot of misdeeds can be conducted by abusing these very important values.
I deliberately don't give any examples, because the examples may derail the conversation and take the spotlight to the examples themselves. All possible examples and evaluation of them is left to the reader, as a multi-faceted mental exercise.
Hope this clears my intentions a bit.