If you work in a place that emphasizes openness, transparency, playing-by-the-rules, is it harder to get people to stand for election to personnel committees, chairships, and directors of this or that? It seems to me that unless you manage to hire people with a strong public-service ethic, or unless you can offer significant financial or other incentives, it might be more difficult to get people to volunteer for jobs that are known to be thankless. Committees are probably less onerous, and more likely to get people simply rotating through, but directorships where the director has responsibility without power . . . well, really, who'd want to be responsible yet powerless?
In a cutthroat department that plays favorites, then, there is an obvious reason to volunteer for committees and to try to become a director or chair: you can protect yourself and your friends, and take revenge on your enemies. I'm not saying I want to work in such a place, mind you. I'm just sayin'.
Updated to add: Dr. Cleveland discussed what's-in-it-for-me here.