John Dalberg 1st Baron Acton said that. No, I don't know his historic significance besides that phrase that is used way too often. Unfortunately, it expresses that idea so well it's almost impossible not to use.
Some people are good with power. Maybe they had the right parents, the right upbringing, the right training, and when they attain a position where they can lead, they lead. Other people go nuts and become tyrants. They become drunk on power without the attendant decency and morality of character to go with it.
You can look around the world and see any number of tyrants behaving badly on their ego trips. Louis XIV said it well "L'etat, c'est moi"--"The state, it's me." He called himself The Sun King. Yeah, he didn't have an issue of being shy and retiring.
I just occurred to me how full of themselves some people get in publishing. They really do wield a kind of power, the livelihood of a writer is in their hands, and they seem to enjoy taking advantage of their position. Sad, really.
I've gotten on an apple kick so I'm going to be tinkering with this image in Photoshop for a while, seeing what I can do with it. It was the original cover image for Bad Apple.