I'd be willing to bet that most of the people who condemn Autozone and other companies for not letting their employees carry would do the same thing if they ever owned a business and were forced to hire people they didn't know. It's just CYA.
I have no idea who the people I'm hiring are, their competence with a gun, or how level-headed they are. Why would I, as the man that could end up going to court or jail over this person, not care if they have a gun with them on my time? I can't allow one and not the other or I'd get accused of discrimination.
As gun owners, we have to abide by the same rules as anyone else. We're not an elite class. The point of a business is to make money, not flip off the man by allowing my employees to carry and do whatever they want.