>>46012356That's literally the only reason it can see. Some Gardifag at GF didn't want their precious waifu to get a 4x weakness that they have no problem giving to with several other Pokémon.
Aggron gets spit-roasted by the two most common offensive types completely invalidating its intended role as a tank. h
Ice literally makes every other type worse when combined with it because it resists fuck all.
Fuck, even Charizard from KANTOOOO gets the 4x Rock curse.
I don't know what the fuck make Shillivoir so special that it can't have a 4x weakness. It's already better then Gallade.