Constantly telling us that though, that "you cant do that", simply because they cant or wont, isnt helping anything, or anyone.
I wouldn't say that it can't be done. I would say, and the statistics bear it out, that it's not simple to do and the odds are against it.
Im simply saying, with a little regular and realistic practice, making those shots is not hard at all. And Im not talking about standing still, and taking my time in squeezing them off in doing so.
This gets to the crux of the matter, but only partially so.
You clearly believe you have a considerable amount of experience shooting on the move and further believe that you have acquired an unusual (statistically speaking) level of skill in this regard. A person with that level of experience AND who has become competent at that skill will have a much different chance of making headshots in a gunfight situation than someone who has never done anything other than shoot at a static target from a static standing position.
However, that doesn't change the advice that one should give. Specifically that trying to take headshots in a gunfight is inadvisable. Why? Because anyone who really does have the skill to take headshots in a gunfight won't be asking for advice on whether to do so or not.
The only remaining issue is the people who think they have the skill to do so but don't. The goal there is to provide enough education for them to help them understand better what their skill level is.
...with a little regular and realistic practice...
Two problems there. "A little practice" has different meanings to different people. I know people who have bought a gun, shot it at the range on one occasion and never fired it again. They would tell you that's "a little practice" and that shooting once a year is "a little regular practice". Shooters like you would likely believe that wasn't practice at all and that visiting the range multiple times a week is "a little regular practice".
As for "realistic practice", it's something that the vast majority of gun owners don't even know how to define. Common range rules restrict "practice" to standing still and shooting slowly at a static paper target and based on what I see at the range, there are precious few that are any good at that. Telling someone with that kind of "practice" experience that "making <head> shots is not hard at all" in a gunfight isn't helpful, in my opinion.
Is making headshots in a gunfight hard? It's not
as hard if you shoot several thousand rounds a year and get to the range several times a month to practice shooting on the move and on a timer, but it's still considerably harder than getting hits while aiming COM.