They should be getting praise and more mentoring, not sure why they'd worry about how the C's are being treated. It should also be clear to the C's that they are not making the cut and either they get better or they leave.

There's something that is very pernicious in the government in Brazil (where I'm from) where in a department there's one person that does all the work while everyone else sits around. You can't fire the non-performing ones or push them because there is a very strong worker protection system for them. Back in college it took me a full week to get my grade history because the person that did all the work was on vacation and nobody else bothered to learn how to pull it or cared if students couldn't get the report.

These are the C's, people that have to be forced to do the work, and that will eventually cause all the work to pile on everyone else. There's no fun in working in an environment like that and its a quick recipe for a burnout.

Government work tends to also have structured pay scales that rise based on time worked and less so or not at all on performance. If the end result of working your tail off or doing the bare minimum is the same x% cost of living “raise”, no rational employee would put in any effort.

It tends to be the reason so many Americans are anti-union. They do a lot of good for the average worker but they also carry along a lot of dead weight that can’t easily be shed.