The overwhelming majority of the average human's life is also spent in conditions where they are on relatively even grounds with everyone else. But once you start looking at what happens when people end up in situations where they are clearly more powerful than others? And can treat those others the way they like and without fear of retribution? Ugly.
I disagree. While there are some spectacular examples of what you describe, and they are indeed ugly, by and large there is wide distribution of hierarchical disparity even in daily life which is more often than not mutually beneficent.
As an emperor I optimize my empire by ensuring that my subjects are philosophically and physically satisfied do I not? I think there is plenty of evidence to support this philosophy as the most sustainable (and positive) of hierarchical models; after all some of the most successful businesses are laterally organized.
I declare this Open Thread open for discussion of Less Wrong topics that have not appeared in recent posts.