Good points in the editorial. I also think that we should look at the worst cases. However, politicians, and the disaster planners who work for them, usually do not want to admit that their plans do not cover the worst cases because that would require very unpopular actions. Two examples come to mind.
In smallpox policy, we do not want to talk about mandatory immunizations or even universal immunizations because the vaccine is risky. But the worst case models show smallpox introduced at multiple points (as would be likely in a bioterrorist act) infecting and killing millions before it is controlled with incremental immunization strategies. (For more info on smallpox.)
On the Louisiana coast, the worst case is New Orleans utterly flattened by Cat 5 winds (most housing destroyed and most trees down, likely on the housing) and then completely flooded. That reality would require serious reconsideration of current rebuilding and levee projects, and would further undermine the real estate market. That makes it politically impossible to consider. Before Katrina, it had become politically impossible to admit New Orleans could flood, which was the primary reason for the late evacuation call and the opening of shelters in the city. A few more years without a bad storm and the politicians will again convince themselves that the city has been protected by the levees.