My take away from this entire thread so far is that if a person with a knife decides to ambush you from close range you're going to get sliced to ribbons and there's pretty much not a damn thing you can do to stop it and survival will be a matter of blind luck or providence (if the person really, really wants to kill you, that is, which they must, or they wouldn't have just ambushed you at close range with a knife).
Pretty much cover it?
I think the point was 1) guns are not magical talismans that make you safe from "inferior" weapons like knives 2) you will likely need to know how to avoid and control an attacker's knife in order to gain time to draw your weapon. These may be things we all already "know," in general, but I enjoy reading about specific ways of accomplishing the second point.
I personally think that you'd be lucky to see a knife at 7 yards or further. I'm willing to bet most knife attacks take place at much closer ranges, and the would be knife attacker would prefer to get close first
pull the knife, rather than show it to you from 21 feet away and charge at you. But, there will probably be other behavioral clues to their intentions. I don't think knife attacks occur out of the blue most of the time outside of prison shankings and other environment dependent situations. There will likely be some kind of indication that the person is angry or hostile, and they may close distance not by charging, but by slowly walking forward while engaging you in argument or conversation. So, learning to read people, de-escalate and extricate yourself from conflict situations apply as always.
Not trying to come off like I know what I'm talking about - I am far far from being any kind of expert on knife fighting, gunfighting, or any kind of self defense except verbal judo. I just don't think this thread preaches quite the fatalism you're reading into it.
George Orwell wrote:
Power is not a means; it is an end. One does not establish a dictatorship in order to safeguard a revolution; one makes the revolution in order to establish the dictatorship. The object of persecution is persecution. The object of torture is torture. The object of power is power.