A 10x person who brings down 20 others to a small fraction of their potential and causes other rockstars to leave is still net-negative. Good management understands this.
(And I'm not sure why I'm downvoted for this. Nothing about that should be controversial?)
Exactly. So the company keeps the guy everyone hates after laying off people that get along. The next people to leave the company are the ones disgusted by the move.
Depends on the company. I've seen the opposite case were such a person was let go, much to everybody's relief. Some people had to clean up his mess, which was genius in the sense that it worked flawlessly, but nobody else could maintain it, so he had locked in a minimal bus factor. Which makes such a move harder to execute, but the earlier the better.
(And I'm not sure why I'm downvoted for this. Nothing about that should be controversial?)