Peoples idea of their own history are influenced by the media (print, film, tv, etc).
The owners of said media often prefer to fund historical content from the perspective of rulers, as this reflects their class character and aspirations. Meaning they have an infatuation with royalty because they do not think of themselves as lowly.
The people then adopt similar mechanisms of reflection to how they view their ancestors in the past.
I say this mechanism of reflection is a political tool designed to entice average people to think of themselves as above average in the past. And thus eliminate any consciousness of historical class continuation.
If you say "what?!" again, I'm just gonna have to assume you disagree but are too afraid to do so out loud.
Isn't it the other way around - people, especially when young, like to imagine themselves as someone special, so the media give them the perspective of the most special individuals they can find? Being a king, on its own, may not qualify - but the popular shows are rarely about "just" kings, it's mostly about ones who did something impressive (if evil; though I agree that last part tends to be edited out).
In fantasy literature, a hero is almost certainly either a prince or at least of royal blood; in sci-fi, he's at least a progeny of a war hero or great inventor. Even in romance slice-of-life, you'll get mysterious amnesiacs, rich CEOs children, shrewd nerds with underworld connections, etc. much more often than statistically possible - nobody wants to read about "normal people", not really (when we think we do, it's just the author writing so well that he convinced us his "normal people" are different!)
I can't rule out the possibility that this natural tendency is being exploited and manipulated in some cases, but the stories have always been about heroes, long before anyone thought of erasing anyone else's class consciousness.