The company I work for fired some people today:
http://andreyf.tumblr.com/post/69289027/shitty-day
Everyone was bummed out (especially those who had to make the decision). I've never really been fired from a job, but I imagine it must be soul-crushing, maybe because it feels like such a "judgment from above". From a management perspective, it puts a spotlight on the shittiest part of companies, also - it destroys the "we're in this together" spirit, and draws a strong distinction between "management" and "workers".
What kind of corporate structure would let people decide to leave on their own, not have someone force them out?
At the limit, you would just reach a no hiring, no firing steady-state with a minimally functioning economy.
The only activity would be new companies hiring until they were overwhelmed by dead weight and companies going bust. (Wouldn't that be a little like firing everyone?) Strange and ponderous unintended consequences lie here!