At the systems level it seems like a stable outcome. Workers don't want to be put on PIPs so if they react in a manner totally opposite what the manager wants and treat them as being fired then they cease to be effective. Managers now have to address performance problems without them or just fire them.

The kind of professional stoicism being advocated for actually makes you easy to mistreat. I feel so bad for my Gen X coworkers who seem to be conditioned that this is the only way to be and seem to have no concept of when they deserve better.