The short story, titled Eight O'Clock In The Morning, is an exercise in awful writing. The protagonist goes around murdering "Fascinators" without any discussion of what changes him from a compliant citizen to this state.
What John Carpenter's story does, in essence, is add fat, muscle, a brain, and pretty much everything else a living organism needs, to a skeleton in the most literal sense. Everything that fills out John Nada's back story and makes him seem like an actual person who thinks and feels is all John Carpenter's idea.
SFF Audio offer readings of short stories in their podcast. Episode 146 is of Eight O'Clock In The Morning. Do not just take my word for it.