What does it mean to be a king in a society that praises democracy?

You are playing with words. A central government represents its citizens, or at least enough of them to grow food and enforce policies on the rest. If the nation has a king, it's because the people want a king, even if he is a jerk. If the officials seem corrupt, it's because they correctly represent a corrupt electorate. If it were not so, the people would refuse to support the regime and the regime would fall. This happened in several countries in recent years. You don't have to throw a government down, just stop holding it up.

Also remember that a government's most important duty is to prevent any other group from taking control. A citizen's duty is to control his government. That is why governments always eventually treat citizens as enemies of the state.

You can see that an occasional collapse is built into all systems of centralized government.