> “A lot of the time, they’re done,” Gadea said of underperformers. “They’re burned out, they need a break. And now you’re asking them to work harder.”

I've seen that once, most recently.

Before that, it was somebody who was trying to get let go on performance grounds, thinking that it would lead to severance (didn't work out).

Before that, it was somebody who got put on PIP, but I'm not sure why, and they were personally devastated and then quit.

Telling somebody that they're fucking up and that they need to improve is one thing, that's just feedback. Creating a structure that's officially "if you don't do X, Y, Z, then you're fired"... just fire them.

My experience with the system was it mostly being abused by incompetent managers who had no clue how to evaluate engineer performance.

Why just fire them? As you showed they can “just quit” if they don’t want to play ball, and some people want to have the opportunity to play ball.