I brought this up is because there is a common misconception the Army/War Department intended the pistol to generally be carried cocked and locked. It simply isn't so.
The reason it is a common misconception is that cocked and locked is the best way to carry the pistol ready for immediate use, and people commonly assume that is how the military would carry it. The Military, however has other ideas.
Many people assume that the "best" way to do it is the way the military does it, and that's not necessarily true, either.
Military carry rules are NOT based on what best protects the individual. They are based on what is judged best to accomplish the mission, and protect the service, overall.
Now, not even the military is going to tell you that you can't load the chamber, when operating in a situation where it was likely you could get shot at. But, the rest of the time, chamber empty!! Always!!
Why do you think that is? It's not exactly to prevent accidents. It is to lessen the occurrence of accidental/negligent discharges that aren't accidents.
And by that I mean troops screwing around with loaded guns. Not a mishandling accident during normal use. The bulk of the military has always been young men. Young men, a certain percentage of whom will get into some kind of mischief to amuse themselves, when not directly under "adult" supervision. A bored GI, standing guard (and particularly during peacetime) with a round in the chamber is an invitation to accident.
A standing rule keeping the chamber empty (and the GI knowing his butt will be busted if he gets caught breaking that rule) goes a long way to reducing the risk of an accident.
Yes, its sort of a safety thing, but its not about the safety of the guy carrying the gun. At any given moment, there are hundred, if not thousands of people standing guard over something, and who actually have ammunition. There are also thousands guarding something with a weapon, who DON'T have ammunition. Been both, many times.
Civilian armed guards are not immune to the same accident through negligent handling and supervision, either, I know of one guy who shot himself in the foot in the middle of the night in a guardshack at a security gate in the middle of nowhere...he wasn't a guard, after that...
Many people just assume its chamber empty due to the risk of carrying a loaded weapon, and there is a degree of risk, BUT organizational rules are also there to reduce the risks from people "playing" (and screwing up) when they shouldn't.
The M1912 and M1916 holsters facilitated putting the gun in action fairly quickly, unlike some European holsters which were designed with protection of the gun put way ahead of ready access.
There are two main schools of thought and design. Ours and theirs.
I'm sure it is due to a combination of culture and history.
Generally speaking, Americans believe a sidearm should be reasonably rapidly available at all times. US holsters generally split the line between fast draw and most protection for the gun.
European service holsters are luggage cases. Studs and buckles and straps...oh my!
Based on what they make and use (historical designs, not current) of both guns and holsters, it seems that Europeans believe(d) that when needed, the gun should already be in your hand, and that safeties are something best worked with the hand not pulling the trigger.
Or, at least, it looks that way to me...