I assume you mean that the flooded areas should not be rebuilt. Because the areas on high ground are fine.
If the Grand Poobahs who decide these things decide not to rebuild the rest of New Orleans, who's going to compensate the property owners? No one can be deprived of their property without just compensation, remember?
We would not "deprive" them of their property. We're just wouldn't pay to rebuild it or protect their location with flood control. They want to rebuild and put in flood control - fine.