Technically a bug, but just not something we had considered in the code when deciding.
"On two occasions I have been asked,—"Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."
- Charles Babbage
Technically the ASims still have a character as you need one to log in. It is just that they don't really play with them as we do. I suppose they could just request all ASims change their race to Mogawi or the ET people - hidden races that don't show up on the race list.