“Civility must hold sway”. That’s the problem right there.
Civility does not exist in a vacuum, nor does it spontaneously arise. Those are both gun control arguments. Civility only exists when there are penalties for being uncivil.
An adult person you do not know approaches you, screaming, cursing and threatening you. If you are passive to his abuse, what is his motive for civility? However, if you have a gun, you have the means, if he becomes violent, of *enforcing* civility. In most cases, without firing a shot.
If you look at situations of defensive gun use against an aggressor, a *common* theme is that the shooter told or showed the aggressor that he was armed and to stop approaching him, and the aggressor did not.
Civility requires fear of a penalty for being uncivil.
People who *are* civil require some means, individually or collectively to coerce those who are uncivil to at least limit their violent actions. Yes, they may legally scream, shout and curse you. But they may not threaten, and they may not attack.
If they do either of those things, civility must be enforced.
You see, suggesting that something could be done better or shouldn't be done at all is pejorative of the person in charge who made those decisions and therefore it is "uncivil." The "civil" thing is to applaud those in charge whenever they do anything - in other words sing the praises of the dear Bolshie leaders whenever they deign to grace you with their presence.