Shooting an assailant in the pelvis is useful because your chances are good of hitting bones; this can immobilize pretty much anyone.
People got away from revolvers in favor of high capacity magazines. The old .38/.357 pistols didnt leave a lot of injured perps. A through shot with a .357 is usually a terminal injury. 9mm? Not so much.
A perforated bowel will give the perp lots of time to reflect on his career choices.