Is this not paradoxical?
The MD-80 series was developed in an age where pilots were supposed to know how to fly and how to avoid stalls.
A stick pusher is a requirement for T-tail aircraft that can become locked into a stall if stalled too deeply. I recall reading that the DC-9 and MD-80 aircraft were apparently tweaked and demonstrated to not enter that regime, so no stick pusher was required.
The stick pusher is not there to keep you from stalling, it is there to keep you from getting stuck in a stall with no way out.