I'd say your observations are dead on. I can only guess that S&W never pushed this gun into the market place for a couple of possible reasons. (1) the cost of manufacturing the extractor system would have pushed the price beyond returns and (2) I don't recall the 9mm as being the dominant cartridge back in the mid to early 80's. It was the NATO or foreign cartridge but here law enforement was still using revolvers. Things changed pretty quick though but investing heavily on a design specific to one cartridge only would be a risky .
Rick
Rick