I think people have a tendency to try to justify their choice of caliber with facts. But the facts are all over the place, so if you pick and choose you can get the backing you desire.
Compared to rifles and shotguns, hand guns all fall into the minor leagues. Except in movies, all popular SD calibers, (38spl,9mm,40S&W, 45acp), are close to each other in performance. Whatever you shoot the best is what you should carry. When you get into the magnum rounds like 357, 41 or 44, you should be aware of over penetration. If your bullet goes through your target and hits something or someone else, you may have serious problems. On the streets I carry 38 SPL +p, 9mm or 40S&W. In the woods 357, or 44 mag. If I could only have one gun, it would be a 357 mag with 38spl+p for the streets, and 357 for the woods.