I agree that this guy shouldn't have been fired. Its a stupid move that doesn't do anything but generate bad publicity, but look at this from AutoZones perspective: A guy comes in and robs Auto zone and they lose 2000 bucks. Maybe an employee goes shot, but they can't sue the company because of paperwork they signed. So AutoZones out a couple grand.
Now on the other hand, AutoZone allows its employees to come to work armed. Now 99% of the people will be perfectly responsible and prob never brandish their weapon or need to use it. But one idiot, just one, accidently shoots someone. After lawsuits Auto zones out millions. The company has a no gun policy to protect themselves, not because they're anti-gun