Not sure about the MD-80 specifically, but I've been told many large aircraft don't recover well from stalls.
They're nothing like the small aircraft. They're designed for efficiency.
Perhaps one of the heavy metal pilots can elaborate.
That's probably why demonstrating stalls for the ATP rating goes like this...
Recover, if you get a stall horn
Recover, if you feel any buffet
Recover, if you feel an impending stall
Recover, if the guy next to you feels a buffet
Recover, if you hear the word stall
Recover, if somebody says a word that rhymes with stall (like mall)
Recover, if you fly over something that rhymes with stall (like a mall)
Seems like the progression of certificates starts with emphasis on recovering from stalls as a private, to ovoiding stalls as an ATP.