Obviously the good man with the rifle is rendered impotent because he is a good man who honors the social compact and will not flaunt his country’s laws. As a result he is disarmed in exactly the places where these crazed zealots go to indiscriminately kill innocents, who choose these places precisely because they know they will encounter no resistance.
Go down the list of mass shootings. All or nearly all of them take place where guns are forbidden by law or custom (I am unsure about that racist who shot the church goers a few months back. These crazies go to schools because they know there will be no resistance. Or they go to movie theaters that they know have signs denying ccw permit holders entry. If these killers went to gun ranges, or large stores that permit permit holders they would be shot dead in their tracks. I know I am preaching to the choir here but “Gun Free Zones” are for all intents and purposes proving grounds for mass murderers - it shows what cowards they are, but we are also foolish to have these moronic laws. It is like putting a sign in front of your house that says “we have cash and jewels but no weapons. Please don’t rob us”.
He's also rendered impotent because people are supplying his enemies with even better weapons.