I think people are just angry inside about the loss and destruction, and the "looters" are about the only thing they can lash out against. I lived in the South, I barely had enough money to get through the day. With gas as high as it is, I honestly would not have had the money to get terribly far out of the city in that traffic. Then what? I'd be stuck on the side of the road. So yeah, I probably would have stayed, and without power, yeah, I would have salvaged canned goods, water, and maybe even guns. But down there, some folks are just looking for a reason to shoot other folks. Like Pull~My~Hair said, the vast majority of the material property is gone, one way or another, and will be written off. Even if the gold watch is still in the store when the owner gets back, they are going to pocket it and write it off.
Besides, who is being called a survivor and who is being called a 'looter' is suspiciously drawn across racial lines.