The NRA and company are trying to sell America one particular line. One that violates human psychology like telepathy violates the laws of physics. It is a story so naïve that it is amazing so many swallow it.
The myth is as follows. Wayne LaPierre famously said that the only person who can stop a bad guy with a gun is a good guy with a gun. Of course that is a misdirection from the greater truth -- the best way to stop a bad guy from killing from the get go is to keep them from getting a force-multiplying gun in the first place -- but it also is based on a false understanding of how human beings work.
The firearms promoters are pushing the ideal of the law-abiding gun owner. These are those persons who own one or multiple firearms, and who are good, solid, decent citizens who can always be relied upon to do the right thing when it comes to using their guns. Including being willing and able to take out the dangerous evil-doer with a bullet if and when the need arises, before the ne'er-do-well can wreak more damage to his innocent victims, and without causing collateral damage with errant aim and ricochets. The very possession of guns makes such responsible Americans even more responsible in their actions, lest they cause harm with their lethal machine pistol or rifle -- almost all guns being semi-automatics these days.
In the context of this mythos, responsible gun owners are supposed to be above criticism for owning and publicly carrying guns. In right-wing world, all must presume that the law-abiding firearm aficionado must be accorded respect, and acknowledged as having good intentions regardless of their politics.
Of course this is nonsense. Everyone who possesses firearms is an inherent threat to themselves, their families, and the general community.
There is a core reason for this. This is because every single person who owns a modern repeating firearm suffers from a grave defect. One that makes them a potential time bomb capable of becoming a weapon of mass destruction.
The defect that afflicts every single gun owner is that -- they are human beings. That is a serious problem because every Homo sapiens is defective. None of us are reliable. Any one of us can lose it and go ballistic as it were.
Say you have two people who are identical in every way, except that one lacks access to firearms, while the other is skilled in their use and has guns in their possession. Assume they are both conscientious citizens who have always obeyed the law, and never caused harm to others.