That may be true. But for the 295 million Americans who don't live in Louisiana, there's only one government that we fund and that is accountable to us. And there's only one government that we rely upon to move into a disaster such as this and competently deal with it, REGARDLESS of how incompetent, corrupt, inefficient, or underfunded the state and local governments may or may not be.
Think back to the 2004 presidential campaign and imagine the reaction if Bush/Cheney had said, "Elect us if you want to be safe from a terrorist attack, or in the aftermath of one. But of course, this promise is null and void if your state or local governments aren't up to the task (regardless of whether we happen to have cut their federal funding)."
In a massive disaster such as this, wherever it may occur in the US, I expect MY federal government to step in and deal with it competently, no matter who's in the state house or city hall. And I would venture to say that most Americans share this expectation (or at least they did before last week).