So because it's hard to be ethical we shouldn't try? Because it is hard to quantify greed it is no longer a bad thing?

Because other people are doing it too is a good justification?

I recently watched the movie "Django Rising" and the character of Leonardi diCaprio troubled me greatly. Not because I thought he was really evil but because I thought he really wasn't. Had I been born in that time, son of a slave owner who was son of a slave owner, brought up surrounded by the values of that time, would I have been able to recognize that slavery was evil, would I have had the courage to do anything about it? Would I have behaved any differently from how Leo's character behaved?