Ethics (good or bad) are not enough alone to make a particular action viable. Usually you need a community of people who are prepared to believe that a particular action is "good". At that point social pressure is enough to push people down a path regardless of the actual benefits or costs. This can be hugely beneficial (charitable donation) or very very bad. I don't think you can get the good without the bad. A lot of good human behavior would be lost of people only acted on logic.