Wait, what about ondonti? They are full-blooded orcs, but also pacifist farmers who hate violence and shed blood only during the slaughter of cattle. Even those ondochi that were captured and indoctrinated by the Zhentarim retain some of their peacefulness and are much less evil than other orcs.
So what's the bottom line? All orcs/goblins/etc are evil due to the fact that they are created by evil gods, which is why even their half-blood descendants must fight evil within themselves or there are still exceptions indicating that the race is not inherently evil ?
