Wrong angle to take. If a criminal can't see a gun, that means the criminal thinks the person is a soft target and is more likely to attack the person.
Logical fallacy. If I'm OCing, I might stop the bad guy, or I might run away. Same could be said for someone CCing. Neither the OCer, nor CCer, want to see innocent people hurt.
False, the way to make people aware of RIGHT TO BEAR ARMS is to use that right. I would retort that this "author" should refrain from using the 1A to write anything so as to not "offend" anyone.
If a bad guy can’t see a gun, then he won’t know he can snatch that gun.
If someone is committing a crime, the most likely person to step in is the one with a handgun on the hip.
Stay safe and aware, and leave open carry for when it makes sense in gun rights demonstrations.