Firing for this kind of behavior establishes a precedent against which subsequent actions/individuals can be judged. By avoiding dismissals, you keep in place the ambiguity and arbitrariness in which toxic, manipulative people can thrive.

I really think ambiguity is the source of all HR problems.

There should be a clear list for each employee of which specific things will get them fired. And which things need to be done for them to otherwise not be fired. And which things need to be done for them to be promoted.

Anything else you're basically saying: "If there is ever a lawsuit between this individual and the company, we will have to assemble the employment agreement in court from a variety of obscure emails and text messages."

What amazes me is that even with that risk, it still seems to benefit the company to keep these things vague in order to keep promotions down, and to make it easier to fire people who are doing their jobs. But I guess the numbers add up.

Personal power politics. They've got enough influence that the loss to the higher-up is bigger for dismissing than for basically handing out a slap on the wrist that basically tells the underling to not get caught.

If your employee is underperforming it reflects poorly on you. Better to trade them around and offload the weight.

Or, if you're really a toxic piece of guano, you foist them off on someone you want to actively sabotage. I get the sense that's the level of bad activity at Uber.

Ill see you that and raise you "And now i have something i can blackmail this person with, since i have all the records and evidence. I can control this person now, and count them on my team, so there is no point in firing them".

Woohoo welcome to the Meritocracy of American Capitalism