Is Emptying N.O. Really a Good Idea?

What do you guys think of the decision to empty New Orleans completely to clean it up & get utilities working before letting the population back in?

Won’t the worst of the worst be the very last people to be cleared out of the city? And couldn’t they do an awful lot of damage—looting and, worse, arson—before the National Guard caught them all?

I know there are big problems with getting even bottled water into the city. But doesn’t it seem a pity to kick out people who are on high ground, with generators, protecting their own property? I’m afraid the insistence that everybody evacuate may turn out to be grounded in the illusion that government officials tend to be subject to, that if they could just get everything 100% under their own control, everything would be so much easier.