Sure, the end state of "everyone hires quickly and fires quickly" is better, but there's an intermediate state where only a few companies use the new paradigm.

Sure, the end state of "everyone hires quickly and fires quickly" is better, but there's an intermediate state where only a few companies use the new paradigm. In that one, the "can get quickly hired across the street anyway" isn't true. And the people who get fired are going to spin narratives about how getting let go was management being stupid and untrustworthy, regardless of how true that is, so you'll wind up generating noise that scares off developers.