Okay, but reference to widely accepted, extensive scientific research should not be discounted.
It is not based solely on terminal ballistic performance, to be sure, but it is based on performance.
The oft-repeated comments about diversity and brawn are pure drivel. Anyone can shoot a 9mm more effectively than a .40. That's basic physics.
And that's why Rob Pincus switched to 9MM some years ago.
It never ceases to maze my how people will, from their experience in hunting (involving different species, different conditions, and different objectives) believe they know more than an entire group of expert forensic ballisticians with their extensive body of knowledge, when it comes to human use of force requirements.
"Stopping power"? Really!
9mm is good enough, that's all the FBI has claimed. 40 is also good enough.
I went to the 44 mag example because when we hunt stopping power is exactly what we want. 9mm won't stop a deer in one shot, and it would be unethical to even try. In contrast even an unethical 44 mag shot will probably get a dirty buck, it certainly has a much better chance.
9mm is indeed easier to shoot. I personally carry 9mm for all the same reasons the FBI chose it- it's cheaper, lighter packing, with more rounds and adequate performance.
My only complaint is the belief that the FBI chose 9mm because it is => 40, 45, or 10mm. 9mm is lesser, but all four will get the job done and 9mm has every other advantage off the field, a significant enough factor to outweigh superior terminal ballistics in this case because all 4 meet the threshold and more time is spent off the field.
IMO 9MM will lose a "Miami shootout", but the FBI no longer cares. The agency has changed. Heavy weapons teams with rifles, snipers, helicopters, etc. Would be standard for such a raid. The 9mm wouldn't have the power but the FBI doesn't think it's officers need to be equipped for such an occasion during their regular duties, basically. For their regular duties 9mm is plenty.
The math is basically thus: If I'm not planning for a fight 9mm is just as good as 10mm in the holster, and in most confrontations equally effective when deployed. In the situations a 9mm would be insufficient, like a battle, the answer isnt 10mm it's a swat team with tanks, rifles, and air support. If however you were going to a battle armed only with a handgun, would you choose 9mm or 10mm? Miami shootout was exactly that scenario and the agency responded first by trying to equip their agents for such a situation. Now though in the modern world an agent won't wind up in a surprise battle so why bother?
Anyways, 10mm > 9mm by far, I choose 9mm anyways.