If your reason for making the choice to carry puny is based on the small probability of actually needing to fire the weapon it is hypocritical thinking to load that weapon.
Your arguments all seem to be based on taking actual facts and then isolating them and carrying them to such extremes (in the total absence of other contributing factors) that they become ridiculous. That doesn't prove anything other than, perhaps, your creative ability.
Caliber has a CHANCE to make a difference in perhaps 1 in 10 self-defense gun uses. That's what the stats say. They don't say it makes NO difference, they say that most of the time
no one gets shot and therefore in those cases where no one is shot
caliber can't possibly make a difference.
Those stats clearly
are not a rationale for leaving your gun unloaded because SOME of the time (maybe in 1 out of 10 cases) you actually DO have to shoot. They don't tell you that caliber is meaningless because logic tells us that in at least some of the cases that make up the 10% of the time when the gun is fired caliber CAN have an effect.
Ok, the next step is obviously trying to determine what happens in actual shootings.
I've quoted this document repeatedly, but here it is again. In the FBI's document on handgun wounding and effectiveness the author speculates that in actual shootings, caliber might make a difference in 1% of shootings. He's talking about comparing service calibers, as you move significantly
above or below that power level the significance of caliber selection obviously increases.
Again we find that while caliber CAN make a difference, it makes FAR less difference than the general public believes. The author makes the point that even a large bullet from a powerful handgun will destroy far less than 1% of the tissue in a human body--just a few ounces. Clearly the REAL issue is not whether 0.05% is destroyed vs 0.045% but rather WHICH 0.05% is destroyed.
The point isn't that caliber makes NO difference, the point is twofold. Caliber means nothing about 90% of the time. In the remaining 10% of the time it sometimes makes a small difference but not nearly as much difference as shot placement makes.
The moral isn't that you should ignore caliber altogether, it's not that you should leave your gun unloaded, it's that you should place the PROPER emphasis on caliber and the proper emphasis on shooting skills. The bottom line is that all the "caliber" in the world won't do anything if you can't make hits, but if you CAN make good hits then nearly any caliber will do the trick.
Once a shooter is making good hits in good time then he might want to consider trying to get the little bit of edge that a larger caliber might provide some of the time--as long as it doesn't hurt him significantly in the areas that matter more.