I think it's just change of habits. For example, in russian "coffee" was masculine gender for long time, until significant amount of people started to erroneously call it in neutral gender. Now rules is "okay" with both.
I like to play with those sort of people by saying that the planets of the solar system are: "Mercury, Venus, Mondas, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Rupert".
While one of those entries is strictly fictional, if Pluto belongs on the list there's no reason to exclude Ceres or Eris (though in the true spirit of Discordianism, I have to stick with the initial, fictional name for the final known planet).