My friends, I am here to tell you that this was not an act of cruel injustice, but a setting to rights of the order of the cosmos.
Pluto was a jerk.
He wasn't notably bigger than any of the other big lumps out there, but as soon as he was declared a planet, he began lording it over his neighbors. Poor Charon took the brunt of the abuse. He bore patiently through constant recitations of "Nyah-hah, I'm a planet and you're nooooot!" and wept quietly in his room when Pluto painted "Planetz Only!" on the tree house. Through it all, though, Charon clung to his dignity. He knew that he wasn't that much smaller than Pluto. He had a solid sense of self worth. And yet...and yet...no one's very excellent mother just sent them nine pizzas with a side order of coke.
Pluto, angered by this apparent lack of reaction to his bullying, upped the ante. He short-sheeted Charon's orbit three nights running and invented cruel rumors about Charon's relationship to Ceres. He was a planet, damnit! How dare this--this--jumped up asteroid not react! He was a planet!
And then, one day, he wasn't.
Pluto retreated to his room, the foundations of his world shaken, to listen to heavy metal and glare at the ceiling.
And Charon had cookies, and sat on the rim of the solar system, swinging his feet. His hand ached a bit from the extensive letter-writing campaign to the Astronomer's Union, but overall, he felt that things were looking up.