Normalization of deviance, soft power, and the fact that managing up and managing down are not the same skillset.

Delegating authority is a velocity/democracy tradeoff. Polling 100k people about where to get lunch doesn't work.

So over time, any time someone does something that might be seen as unjust, if it's within the error bars for "unusual but not a hard line", shifts the line more and more, especially if the people in question are good at controlling what the people above them hear, or calling in favors to shield themselves, until you wind up with sentences like "well of course they got fired, they were working on $THAT_PROJECT, and everyone knows $MANAGER hates $THAT_PROJECT".