Your comment reminded me of a quote from Alan Moore

    “The main thing that I learned about conspiracy theory, is that conspiracy theorists believe in a conspiracy because that is more comforting. The truth of the world is that it is actually chaotic. The truth is that it is not The Iluminati, or The Jewish Banking Conspiracy, or the Gray Alien Theory. The truth is far more frightening - Nobody is in control. The world is rudderless.”

Although he's talking mainly about conspiracy theories, I think it applies equally to "royalty" as you put it. People need someone to be in charge, and they'll latch onto whoever or whatever they think will satisfy that desire.