There is an interesting interplay between power corrupting and corruption empowering. The causality does not go one way.
Dictators, unlike Democrats, depend on a small coterie to sustain their power. These backers, generally drawn from the military, the senior civil service, and family or clan members, have a synergistic relationship with their dictator. The dictator delivers opportunities for them to become rich, and they protect him from being overthrown.
If you're running a dictatorship, you don't really have to worry about the welfare or the property rights of the ordinary citizen. Only the people who keep you in power, a very small group, matter.
To understand why dictators fall, it helps to recognise factors that produce a perfect anti-dictatorial storm. Barring missteps such as those that led to Gaddafi's undoing, a dictator's survival can be at risk because of newness in office, poor health, or old age combined with economic trouble.
