And the 9mm does that better than the 357mag?? The answere is obvious. LE wants a auto loader and not a wheel gun. They are easier to shoot faster, lighter to carry, absorb recoil better,and hold 3 times the amount of ammo. I would bet you could put a modern day 9mm bullet against the old 37mag for one stop shots and you could hardly measure the difference. With pistols, regardless of ANY caliber, its about multiple rounds on the target.
Because most of us are civilians, not LE or FBI who want something that will shoot through windshields, car doors, etc