You have a point, however, if the safeguards worked as they were supposed to (levees, storm swell barriers) we would not be having this conversation. Also, most of the city was not destroyed.
Finally, we need a port city in one of our largest ports. Its a matter of economic imperatives.
It might make sense to A) evaluate which places are good candidates for safeguarding B)reinforce existing safeguards and C)develop better plans for evac and preservation of economic infrastructure.
Normally I would say that the gov’t is better than me on doing this but my faith in that has waned on this particular topic.