New Delhi, April 23 -- The sudden exit of a chairperson is often accompanied by off-the-shelf explanations like 'personal reasons', 'strategic realignment' or the pursuit of 'other opportunities.' The recent abrupt resignation of HDFC Bank's chair was a reminder that at the summit of corporate power, where the air is thin and minutes are curated, such reasons are rarely taken at face value.

This is curious because a corporate organization chart resembles something between a pyramid and a theological hierarchy. At the base: employees. Above them: managers. Then executives. Then the CEO, the top boss. And hovering above all, a board of directors. At the apex is the chairperson, the one who is theoretically in charge of those who are in cha...