I have seen several times. By the responses, so have many others.
IT companies are complex rascals requiring many hands with many skills. Most of these skills are simply experience. A few, unique ability. Management, typically, has none of these.
If an IT firm has a fully documented system, an ITIL of policy and procedure covering all aspects of the system and a training system to utilize it, all is well. Any single employee is no longer indispensable and training can be done by any competent instructor.
This rarely happens. Documentation is costly, time consuming, and none wish to do it. A firm that is trying to squeeze every denari from the stone that is IT will never devote treasure to that which is of not immediate profit.
Middle management usually has no concept as to how to create an encyclopedia of operations and could see it as a way to eliminate or weaken their position in the firm. The MM's also have very little idea how daily ops are carried out although hubris convinces them otherwise.
Blood, this they, the C level muckety-mucks, the lovers of coin, have a passion for spilling. How they get the idea that people are costs and not creators of profit is beyond my capacity.
Anyway, nice to see ignorance, greed, and basic head up your backside stupidity punished. For once.