>>25130159I'm not saying Ground types are bad, I'm saying that many Ground type pokémon are not really that inspired or that interesting. (There are exceptions, of course.) For the most part, they just don't go out of their way to make good Ground types beyond "make an animal that digs in the sand". They could use some life.
Also, as much as Earthquake is a Ground type's bread a butter....it's Earthquake; a myriad of pokémon that aren't Ground types can learn it.