There is a certain physiological response to conquest that goes beyond satisfaction, especially in males. For example , the fans of a football team having their testosterone levels go up after a win. This translates to every sphere as some kind of reward to domination. That said, just because it's evolutionarily selected for , doesn't mean power relationships and dominaance have any kind of legitimacy or optimality. They are just as primal as our urge to kill, and should be viewed with suspicion.