I find that approaches like those outlined in the article tend not to think in terms of the institution of public service, and what allows it to function optimally, but through a much narrower aperture, in terms of things like pay costs, perceived fairness of compensation, and such. That's not to say that total compensation costs should NOT be part of how one maintains an optimally-functioning public service. Rather, it is part of an entire system that one has to consider, not just think about money in isolation.
As for compensation itself, I think there are a great many whose attitude is to pursue a "calling" without feeling like they are penalized/punished for doing so. That is, prosocial impact IS important to them, but they do not want to be martyrs. A modicum of stability and comfort helps to justify the choice in their own mind.
In some respects compensation levels just slightly below the private sector may well entrench the self-perceived value of their role. I refer people back to the classic work on "cognitive dissonance" from Leon Festinger and colleagues/students. Sometimes, when we are undercompensated for doing something, we can inflate the perceived personal meaning or importance of the task/action to ourselves, as a way of rationalizing why we were not compensated as much as we would have preferred. I.E., it must be important, or else why would I have done it for less reward than I should have, or felt I deserved?
The disjunction between public perception and reality is that public sector compensation rates ARE often higher than private sector...for lower level jobs. Once you move upwards, though, compensation rates tend to be lower than the private sector; what some like to refer to as "wage compression". Of course, some of the loudest complaints come from those who have low paying jobs in the private sector, and are envious of their public sector equivalents, or those in lower paying jobs who resent management or anyone making more than them. You will generally never hear complaints about government pay from a consultant in the private sector making $40-60k a year more than I do for the same work.