I think the folks who stayed in Orleans for the Hurricane fell into 3 categories. First, those who simply didn't understand the damage and threat of a hurricane...those who simply thought they'd wait it out in their house like typical storms. Second, those possibly didn't have cars...and expected someone from the Federal government to carry them out (which isn't the norm for any hurricane). And third...those who anticipated a great robbery and crime chance...and just plain knew cops wouldn't stop them. NO is special...its not Miami or Houston or Charleston. NO is loaded with people who are simply waiting for their next welfare check...and live from month to month off that. They may seem shocked...but folks in Florida live through this all the time.
The other factor, "Aw, we will be ok, the "News" is always hyping and exagerating, it will not be so bad".