When they're not ineffective, we call them dictators; democracy is about debate and compromise and thus is inherently inefficient, limiting its leaders to less than their best. And—fortunately, as we've seen with Rob—to better than their worst.
As for being self-serving, that is the very essence of our free-enterprise system.
We get the crap politicians we deserve because, unless there's some scandal—or a pothole on our street—we go to sleep the day after the votes are counted, waking up only to sling blame and demand more for less.
Who would want such a job?