It isn't. However those arguments are against PUBLIC gun free zones, with an extension to businesses; and there is a debate to be had there that will probably

It isn't. However those arguments are against PUBLIC gun free zones, with an extension to businesses; and there is a debate to be had there that will probably need a supreme court case to decide. However I've yet to hear anyone say that you should be allowed to carry a gun into someone else's home against their will. In fact most gun owners would say you'd be well within your rights to shoot an armed intruder on your property. It's directly analogous to my previous example. It is illegal for businesses to deny service on the basis of skin color. It isn't, however, illegal for a private residence to do so.