Associate
For a change in here I cite below what is perhaps a bit of positivity for civilians being armed: ...
Sometimes having civilians handy with a gun can save lives...
Legally armed civilians in the USA regularly stop armed criminals from committing murder or armed robbery. Here are a few cases recently reported in the US media:
Gun-toting dad who thwarted mass shooting despite being shot in head now training others on self-defense
Pregnant woman shoots potential robber at Houston gas station
Chicago concealed carry holder foils late-night armed robbery attempt
Armed Las Vegas worker stopped likely mass shooter in his tracks: expert
Philadelphia concealed gun holder acted in self-defense, fatally shooting attacker at cemetery: DA
There were school shootings that were ended by legally armed civilians too. The liberal media often neglect to report on these sort of cases though as they don't fit into the narrative that civilian gun possession = bad. Of course, we never hear of cases where a civilian used a legally owned firearm to frighten away a violent criminal without opening fire on them.
It all comes down to preventing high-risk people from getting firearms. In most (all?) US states it is already a crime for convicted felons to own a gun and in many US states they bar ownership by people with serious mental illnesses. But they have the gun show loophole and patchy (state-level) background checking combined with a large black market for firearms sitting beneath the huge legal civilian firearm market.
Some parts of the USA are so violent that you'd be glad to have a legally held pistol and the right to carry it in a concealed manner if you had to live there. Therefore, it would be unfortunate to force law-abiding people living in dangerous areas to give up their legally held guns because nutcases keep going on shooting sprees.
Bear in mind too that there is a lot of case-law that has established that the Police in the USA do not have a legal obligation to protect the lives of civilians above all else. That's why the former deputy for the Broward County Sheriff's Office who failed to go into the Marjory Stoneman Douglas High School when there was an active shooter in there killing 17 people was found not guilty recently, despite him being the designated first-responder to a school shooting there!