The problem with the 10mm is that it came late too the show. You see a few years before the 10mm came out, back in the mid-1860's, a company called Colt came out with a round called the Colt .45. Then about fifty years later, a guy named John Moses Browning cut the .45 cartridge down to make it easier to use in a semi- automatic handgun. He created a pistol to fire this round which he called the Colt .45 automatic, or the 1911.
Then about eighty years later some jealous Eurotrash gun slinging wanna bees were so upset about the USA's superior .45 cal. round that they tried to upstage those silly Americans with the 10mm.
Fortunately, most people saw through their veiled attempt to upstage the Americans and demanded that Glock produce a proper handgun chambered for the .45 cal. round. Gaston Glock, being a reasonable sort, quickly introduced the Glock 21 chambered for .45. Since then most Americans have dropped the 10mm in favor of our home grown .45 cal.
If it ain't broke don't fix it.....
-SS