I understand. But they do. Not so much here locally. But still, so many are misinformed about firearms or even the laws, they overreact. Personally, I do not want anyone to know I am carrying a handgun. I agree, this action by Walmart will have zero impact on someone wanting to shoot others in their stores. Like you said, criminals do not care about laws anyway and would naturally want to conceal their weapon, or simply run into the store with a rifle and start shooting.
But it will help to keep people from feeling afraid and with all the media attention to these latest shootings, they will feel uncomfortable seeing anyone with a firearm on their person. At best, other companies which sell handguns and ammo for rifles like the AR-15, will benefit from this decision. Like I said, Rural King is just across the street from our Walmart and there are several other gun stores around, such as Vance Outdoors. I bet they are smiling at this decision by Walmart.