My assumption has always been that it's never actually supposed to have been about "improvement", just about trying to scare people into submitting more to mana

My assumption has always been that it's never actually supposed to have been about "improvement", just about trying to scare people into submitting more to management demands. If your manager in a stack-ranked company decides to tell the team to work overtime on the weekends to get the release out faster, no one wants to be the only one to say no when you're all quite literally competing with each other to not be in the bottom. It's not a coincidence that stack ranking turns unreasonable demands from management quite explicitly into a prisoner's dilemma problem.