My point in #28 was in direct response to Buckrub in #27 who was disparaging those who only practice shorter "defensive" distances. You seem to take that to mean that my point is somehow that a handgun is a short range tool. I've said numerous times that I believe it's possible to use a handgun at longer ranges, but it's inefficient at it, and given the chances at being in a long range shootout being very slim, it doesn't make sense, from a practical, defensive standpoint, to train further out than 50 yards or so.
I even showed a situation in an earlier post where an Air Force SF fired 4 shots at 70 yards with an M9, and hit 2 out of 4. That's extraordinary. You will not find much better practical, defensive shooting, in a real life situation than that. 125 yards, in a shootout with nothing but a 1911 is a sucky place to be against a shooter with a rifle, and your chances are very slim. In that situation, I'd be wishing I had a rifle. Just the same as I'd be wishing I had a handgun in a situation where I was 10 yards from an aggressor with a handgun, and all I had was a knife. Could I win this fight? It's possible, but improbable.
In your scenario of unloading a 1911 at 125 yards as quick as you can, you're right, I wouldn't want to be in front of that, even if I were prone, and all you had was about a 10 inch target. But if I had a rifle...well, I'll let you draw your own conclusion. I can empty an AR magazine very quickly, and I'll bet I can get better than 75% on a human target with it at 125 yards. Unfortunately, now we're degenerating to what if's, and that's rarely constructive.
Is it possible to hit something at 125 yards with a handgun? Yes, of course. Is the book full of crap? Without a doubt. Is a handgun a good weapon for those kind of ranges? It will work, but it's far from the optimum tool. Is it a good idea to practice a bunch of different disciplines? You bet. It's good to be prepared for as many situations as possible. My training is limited to 20 yards, mainly because most of my shooting is done at a 20 yard indoor range, due to a variety of reasons. But if I can get out to the nearby outdoor range, I'll push myself to 50 yards. Rarely will I go out further than that with a handgun, mostly because it's not practical to use up a ton of ammo past that, though I will go further, just so I can get a feel for it, and to figure out how, just in case.