Most companies that employ knowledge workers make hire/fire decisions using tools like performance reviews and 360 evaluations, @fretfulmother. Every decision may not be perfect, but a manager who makes too many poor choices will get weeded out herself. That’s how every high-performing private company does it, and it’s not clear that they would be better off with an inflexible workforce.
I’d guess there’s a middle ground that ensures poor performers and burnouts can be dismissed but protects the majority against arbitrary actions.