There just is no reason to shoot anything smaller than a 9mm round in this day and age, "for self defense". Only force of habit , hobbyists, collectors, enthusiasts, or unfamiliarity with why these other calibers are even used as much as they are.
They were at one time the available ammunition for the smallest handguns made at different times in history. If there would have been a more powerful gun in a compact size, the masses would have used that.
When the 32 and 380 were hot, "up until the year 2000 "around", there were no small 9mm guns made. After the 32 seacamp, which proves that people wanted a small gun that had more stopping power, as guys are still waiting for guns the ordered 15 years ago, "lol". The next one was the 380, Seacamp,kel tek and LCP , the LCP was still the hottest selling ccw gun, last year, "every gun manufacturer out there jumped in." They all went to the mini 380's, then came the mini 9's, and many went to a 9mm, ,why? you ask, because it did the same thing as the last 2 big improvements, it allowed you to carry a larger bullet than the 380. Now we went into 45 land, with the XDS. That will be the end all carry caliber, "for now".
When you can shrink down a 45 and make it a carry gun size, you just hit the big bulls eye. it's not an opinion it's a trend, and a logical progression. As folks learn about guns, they want a gun that will dispatch an aggressor to the promised land with as little pause as possible. Now we can waste time arguing about it forever, but the big 3 calibers are finally here in a compact enough package for just about anyone to carry.
So having a Mak, or a snubby, or a Colt 1903, while still capable of killing anyone if used properly, are not optimum, they have a coolness factor and are fun to shoot, but we have improved upon them, as personal protection, as we will improve upon these. My XDS, or Kahr, can go any place I go, why carry something less efficient. As a range toy I can see it, or as a plinker or collectable,or just a possession, if you are going out with the family, take a bigger caliber, it will stop bad guys faster, especially since they are marginal to begin with when compared to a long gun.
This is just my thought and opinion, I am sure there are good arguments that can be made that differ. But we see the trend towards better ammo and larger caliber, mini guns. That cannot be contested. It may have hit it's peak because of the control factor with hi powered ammo.
It will be interesting to see the next big case when someone uses a 45 loaded with powerball ammo on a bad guy, or a "Taurus judge" using shotgun shells. The press should have a field day with it.
It's amazing that we don't actually see more of these types of defensive shootings using say a saiga drum fed 12 gauge. Maybe it's safer than they tell us.