Management has two functions.
1. To provide those who work under you with the tools, resources, etc (as best as your budget allows at least) to do their jobs in the most effective and efficient way possible.
Everything else is extraneous and self-serving.
Granted, people dont usually go into management out of a sense of altruism, they go into it in order to better their own lives, so a certain level of taking advantage of ones power for ones own gain is at least understandable, even if the ethics of it are perhaps questionable. Still, if you're not doing both of the two functions listed above, or only doing the second, then you are not a good manager. In fact, I'd hazard a guess that says that if you do the first part of the job well, then you probably wont have much of the second part to worry about (especially if you do that part well, also).