If its one thing that One Piece has tried to drill into our heads since the beginning, its that nothing is as black and white as good and evil. Marines fight for justice, but even they have their own subjective perspectives on justice. Pirates fight for their freedom, whether that means freedom through fear and dominance or freedom through respect and support.

Right now everything percieved as "good" within the realm of One Piece is written by the WG, which we obviously know is corrupt and manipulative.