Bureaucracy by design leads to centralization of power by the leaders. Leaders also have control over sanctions and rewards. They tend to promote those who share their opinions, which inevitably leads to self-perpetuating oligarchy.
People achieve leadership
positions because they have above-average political skill (see charismatic authority
). As they advance in their careers, their power and prestige increases. Leaders control the information that flows down the channels of communication, censoring what they do not want the rank-and-file to know. Leaders will also dedicate significant resources to persuade the rank-and-file of the rightness of their views.
This is compatible with most societies: people are taught to obey those in positions of authority. Therefore the rank and file show little initiative, and wait for the leaders to exercise their judgment and issue directives to follow.