Jeepnik, you're spot on!!!
Let's put the 10mm in perspective. REAL 10mm 200 grainers exiting the muzzle at 1200+ fps may not be fun for the vast number of shooters. Just because it has a 10mm head stamp doesn't mean it's loaded to real original 10mm standards.
What it BECAME was the Fed lite 10mm (180 gr @ ~950) which led to the development of the 40 S&W in a pistol with nearly the same grip size that held 11 rounds and the feds STILL couldn't handle it
STILL couldn't handle it? Sheesh! What's next? The .30 carry or .380's with 30+ rounds to accommodate Bambi secret agent and wimp men?
Anyway, the thing about the fed lite ammo in 10mm it passed every penetration and expansion test, and it as well as the .40 are potent enough pistol cartridges.
Anyone that thinks differently should see pepper poppers setup to not fall on a windy day laugh at multiple 9mm shots or dead wood bowling pins which go down handily with a .40 NOT short and weak.