Maybe that's because there are people who're actually like that in the world? Everyone wants power...and what's more powerful than the government, the royalty, the Pope, the Emperor? Why, a god obviously. There have been numerous people who've become so drunk with power they wanted to be reminded of how powerful they are by trying to be called a god. There were a few roman emperors who did just that, a few popes in the middle ages, and let's not forget the most famous example of a person who wanted to become a god....
Yeah. It's just a common symbolic thing, really...Because why settle for being an emperor of the world when you can be the emperor of the
entire friggin universe? Even the ruler of the world has to play by its rules...a god can just go "Screw the rules, I have power" and do just that.