I get the idea of gun-free zones, some people are afraid of guns. They think if they post that a certain establishment is Gun-Free that the criminals will not walk into the place with a gun. They'll toss them in the trash and realize the life of crime they've chosen was wrong and they'll proceed to make amends.
When you establish a place a gun-free zone the ONLY people who respect that are law-abiding citizens who were not the problem in the first place, and you actually make that place more dangerous because of it. Two big gun free areas? Chicago and Baltimore. Check the statistics on gun violence in both those hell-holes and you might wonder if the criminals just aren't seeing all the posted signs.
Me? Don't want my gun to come in? No problem. I'll shop elsewhere. Because I don't feel safe in a place where only bad guys have guns.