Well, all Sims that are a certain lifestate are still Sims. But strictly talking about the normal ones, I mean, yeah. I thought everybody knew this, honestly.
Aside from being fictional beings within a game, they are human. And since the word "Sim" comes from "simulator", the game being a real-life simulator ( more or less ), they can't call the series "The Humans".
Plus, if memory serves, the normal lifestage for the Sims in the Sims 3 was referred to as "Human" with the Supernatural EP.