Yes there is always room for improvement and we honstely do try to do this. The staff talk daily about ideas and possible changes that may inprove the server(s). We hear more then you think. Just because we don't act on it or say no doesn't mean we didn't listen to it. There is always a reason why we do something. in most cases a small change will in fact impact alot of other aspects since it is just how Arma works.
The staff aren't unhappy with there roles, we are unhappy when players feel entitled or down right rude about things. We understand that people work to get to certain roles within the game and that is what we want but at the same time people have to understand they will not always get there or won't get there in the time they wish. I've currently got 2 moderators in training and they both would like more but they simply have to wait it out. this same thing applies to APD, R&R and the News Team. I myself have devoted over a year to this server and so I do understand trying to achieve something and it not happening when I want or at all.
To touch base on your example of a staff member being demoted, we have actually done this. The problem was the players got into a mindset after that basically being "fuck it I dont care anymore" when all they had to do was correct the issues and they would have been given another chance.
In the end we do listen, whether you see it or not. The only time you have reached the end is if your permanently banned otherwise anything is still possible.