I don't think its an issue of who you are going to serve CO, I think the issue is banning guns and then getting robbed at gun point. They have every right to say we don't want guns in our establishment and many places in North Carolina have such notices. I don't think anyone is saying they don't have a right to ban those weapons. But, they should be prepared to pay the consequences.
I do remember a restaurant in Jacksonville FL (St John's Seafood, Blanding Blvd) that was robbed at gun point and not one but two patrons pulled out weapons and shot the robbers
Honestly, since these robbers came in through the back door, I don't think a room full of guns would have done much good but who knows? I guess a room full of homosexuals could have stopped this robbery by doing the thieves hair.