Two reasons mainly. First and less charitably, managers and executives are a self-perpetuating phenomenon. They’d have to be the ones to slit their own throats, and they won’t. The second and more depressing reason is at the core of much human misery from politics to business: it’s better than the known and proven alternatives in most cases. Like what passes for democracy these days, it’s a lamentable mess, but still preferable to the proven alternatives on offer.