You obviously are not familiar with police training or self defense in general. TV & theater (where people get shot in shoulders & knees & fall immediately) are not reliable sources for information. In real life, there is no stunt man being blown off his feet or through a window or becoming become disabled from a hand, knee or shoulder wound.
"Shooting to Kill" is not the goal. Shooting to stop is. Defensive shooting means aiming for "Center of Mass" partly to increase the chance of stopping an attack AND also minimizing the danger to innocent bystanders. Aiming for a small, moving target like an arm or leg increases the chance for a miss, which endangers bystanders.