My game theory is a bit rusty but I remember the pareto frontier as referring to an equal overall utility condition while a pareto improvement requires no participant becoming worse off. In other words you can move along the frontier by negatively impacting other players (which means by not making pareto improvements). This situation makes the players adversaries because there are no longer, strictly speaking, benefits from cooperating.
A thought: if an agent has weak comparative power it makes sense to avoid intellectually investing in such things and to simply assume that the governance regime is either good or bad and then determine whether its good or bad by whether you think things are getting better or worse. This is the simplest decision method, pure black and white and as such represents minimizing intellectual investment.
Minimal intellectual investment is rational if you don't have reason to believe it will effect the decision matrix in a meaningful way and you find such intellectual effort unrewarding (negative utility of the work is more than positive utility of exercising limited power).
Obviously this goes against the point of LW but since we're talking about educating the plebs...
I think we're all a little guilty of using the term zero sum as a substitute for destructive or wasteful competition. Probably better to just call such situations "bad games" heh...
Looks like an issue of utility vs truth to me. Time to get deontological :) (joke)