Well, the carbine was designed for rear line use. Those fellows whose job was not front line but those other necessary jobs that kept the war moving.
But the main point was aimed, poor pun, at the service or personal defense weapon, the sidearm.
No sidearm will ever take the place of a rifle in a front line situation. In close quarters, urban situations, the pistol does have some benefits. In a personal self-defense situation at home or on the streets, it is often the only means of self protection.
The question had to do with penetration, or should penetration take more of a front seat in one's personal choice of pistols. In the woods/fields it does because of the four legged critters one may encounter where knockdown is not the primary consideration but penetration is considered more valuable. Black bears as an example.
With the proliferation of body armor, and with the understanding of its use, is penetration worthy of taking a front seat over large and slow?
Now the question was not to knock the .45 or such but to question the choices and see if the other options brought fourth were worthy of more consideration.
Blessings