In most companies, the formal hierarchy is a matter of public record - it's easy to discover who's in charge of what. By contrast, natural leaders don't appear on any organization chart.
Online hierarchies are inherently dynamic. The moment someone stops adding value to the community, his influence starts to wane.
Over the centuries, religion has become institutionalized, and in the process encrusted with elaborate hierarchies, top-heavy bureaucracies, highly specialized roles and reflexive routines.