Finding security in mediocrity is an exhausting process. You can only work so many hours, fret only so much. Being a slightly better typist or a slightly faster coder is insufficient. You’re always looking over your shoulder, always trying to be a little less mediocre than the guy next to you. It wears you out.
Organizing around the average means that the organization has exchanged the high productivity of exceptional performance for the ease and security of an endless parade of average performers.