Exactly right. But we know that people are human, and make errors. In fact, that's why many rules of proper handling exist - to reduce the chance of human error.
Not at all - you always have to balance the equation of how often, and how bad. If the logic you just expressed was right, and we did assume that not matter how rare, it's best to have your firearm ready to fire... then the rational thing to do is to carry with a round chambered, and the safety off, and the gun in your hand, and your finger on the trigger. This is the "most ready" position. However, we all realize this is foolhardy - the odds of unintended discharge skyrocket.
You have to figure how often it leads to accidents (and how bad) - versus how often it helps (and how much.)
You say it's better in .1% of cases... I say it's probably way less than 0.001%.
If you're in the mafia and opposed families currently have hits on you, maybe the odds of someone stalking you are high enough that keeping one chambered can be rationalized... but truth be told, they'll probably get the drop on you, and you'll never even draw, so chambered or not is irrelevant. Meanwhile, the number of safeties between you and unintended discharge are reduced.
If that were so, I'd always be charging it to 100%. But I'm not. I keep it below 70%, because that's safer for the battery than 90%, never mind 100%, and 70% is plenty the vast majority of the time. And I don't plug in again until I'm below 50%, unless I happen to know I plan to drive somewhere far in the next day.
I need a reason to take an affirmative action that has a downside - and "maybe will need," all by itself, is never reason enough.
