This is a great list, to elaborate on #4, I think there's another factor at play related to the social implications of Dunning Kruger. To be specific: ones sens

This is a great list, to elaborate on #4, I think there's another factor at play related to the social implications of Dunning Kruger. To be specific: ones sense of ones own productivity and value to the company is not very well correlated to actual performance. For new hires, management doesn't what their value will be, so it really comes down to market rates and negotiation based on the limited signal. If you make a bad hire you can chalk it to classic market-for-lemons problem and you deal with it via pip or letting them go. However once someone is established, their performance is more or less well-understood by their peers. It's at this point that the disconnect between ones own perceived performance and the broader perception becomes deadly, because peers talk, and if one of them gets a fat raise and the other doesn't then it becomes a whole can of worms. The merit of the situation will get lost in the individual perceptions and entitlements which is likely to result in an overall morale hit one way or another. Sure this can happen with new hires, but it's more easily explainable, especially in the current climate where market rate has shifted a lot and so you literally won't be able to hire if you don't play the game.