Leon, I think most of us here will agree that bullet placement is key. That being said, however, there are a few things to consider in that particular shooting.
First, the shooter was pretty much within what I call "belly button distance." He was just a little over four feet away.
Second, the Archduke and Duchess were seated in a vehicle...no chance to either flee the scene or attack their assailant. (This is significant because in a self-defense situation, we want a bullet with
stopping power.) Ferdinand and Sophie probably could've remained somewhat ambulatory for a short time after being shot (even considering the seriousness of their wounds) and, had they not been constrained and had been of a violent nature, they could've attempted an assault on the shooter. After the shooting, they both remained seated upright in the vehicle while traveling to the governor's home for medical care.
Third, the first shot hit Ferdinand in the jugular, yet he remained alive until they reached the governor's house. In fact, when he was asked about the extent of his injuries, he replied, "It's nothing."
So, while a .380 is certainly deadly, a heavier, more powerful cartridge would undoubtedly be preferred to produce increased shock and stopping power.
That being said, do I occasionally carry a .380? You bet...a Ruger LCP when it is difficult to conceal something more powerful. Do I feel inadequate? Not really, but I have to realize its limitations. As I alluded to previously, the .380 is a "belly button gun." It was designed to be used up close and personal.
I'm not going to be using it to take shots at 25 yards. It won't be used to stop a charging black bear. Nope. It is to be used when I'm confronted in the parking lot of the grocery store late at night by Jimmy the Creep demanding my Social Security check. Yep...belly button distance. Close enough to effectively empty the magazine into the designated target...enough to either stop or completely discourage further unwanted behavior.
Just my view from the saddle.