I seriously doubt that the Glock will be in service for 100 years. If for no other reason then the geewiz boys will demand the next big thing.
It has been years, but I have personally put many thousands of rounds through an old government issue 1911a1 without failures. Heck we once put 5,000 through an old Argentine copy. You guys also have to remember that military handgun use is different then civilian or police use. It is a last ditch or specialty weapon not their primary arm. A smaller number of rounds is not a real problem if there is sufficient knock down power. Not to mention the steel frame can also be used as a club.
While I can't discredit, nor would I attempt to, discredit the fact that they'll run for thousands of rounds, are you saying other options won't? In your point, the only advantage I see in having a 1911 over any number of other options, is the ability to use it as a club. Let's please not let this boil down to a matter of "knock down power". That can/will be argued until the ends of the Earth. And again, all of the guns I mentioned offer the .45 so I think that's a moot point.