Quote Originally Posted by Othesemo View Post
It would also have the advantage of not punishing one particular choice. There aren't many other types that don't interact specially with one of either fire, water or grass and not the others (fighting, dark, psychic and ghost, assuming no secondary types like Bulbasaur).
The most obvious one (and I'm surprised it took them this long to come up with it) is, of course, Normal-type.