When power is attained through theft, it should come as no suprise that our leaders are thieves.
Discussion
Yes. Add that those who have no interest in power will never seek it. Hence the self-selection of the power-hungry toward positions of power.
The next layer is hierarchy. In a social hierarchy, loyalty trumps competence, since competence can be hired for a price on a need-to-have basis, while loyalty can't be bought. Over time then, hierarchies tend toward rank-based loyalty where merit is washed away. In short: corruption.
Yes, agreed. I believe this cycle will continue until the corruption is so abhorrent, and the thievery so obvious, that people demand different incentives. Unfortunately, I think we still have a way to go before we reach this point.