Yeah, because sticking with a first generation auto-pistol whose design was seventy years old at that point is a great idea. Also add in the fact that most of the USArmy's stock of M1911's had been rebuilt two or three times each by the 80's and you're really looking at a weapon to see out the 20th century.
I actually quite like the Colt 45, but this constant banging on about the thing like it's a doomsday device is plain dumb. If you want a .45 pistol for your military then fine, but pick one that takes advantage of the last hundred years worth of improvements in design and ergonomics.
Actually, Colt developed the Colt SSP, which, for all intents and purposes, was an updated 1911. It was chambered for 9mm though and lost in the trials to the M92 anyway (from what I've read, like most Colt developments from the 1970's on, it was quite a poor performer).
The point about the .45 ACP most people miss is that the U.S. military was going to switch to 9mm NATO no matter what, specifically to standardize ammo and lighten the combat load.
The Colt SSP, had it worked, probably would have ended up the M9, and, as mentioned above, it was basically a modernized 1911A1 (DA/SA, staggered mag, 3-point dots, ambi safety switch, combat hammer, etc...) but it was going to pack the underpowered 9mm too.
The 1911A1 had to be upgraded, that's a fact, but people focus too much on the M9 being 9mm, rather than .45 ACP, and blame the weapon rather than the philosophy that implemented the change in chambering.
The M92 is a perfectly good pistol, and it's even desirable when chambered for a round with good man stopping power (.40 S&W or .45 ACP for example) so I'd say the problem with the M9 is more a matter of the ammo being junk, rather than the weapon itself.
As for weapons that never should have seen the battlefield, I still say the M1 carbine.
If it can't penetrate heavy wool clothing, the weapon's just going to get troops killed to no good end.
My grandfather was part of a 105 crew in WW2 and after surviving The Bulge (by using first a Garand inherited from an unfortunate infantryman, then a 98k and captured ammo from an equally unfortunate German who got too close to his foxhole) he sent a letter home from the hospital for his Remington 12 gauge auto and carried that through the rest of the war.
He told my dad once that it was either that or just carry around a sharpened entrenching tool the rest of the way, because he absolutely hated quote "That worthless hunk of metal and wood.".
His youngest brother was a paratrooper. Got dropped into Normandy with one. "Inherited" a grease gun a few hours into the fighting and never let go of it for the rest of the war.