I agree with you. BUT what you are arguing for is essentially that President Bush should have FORCIBLY seized authority from "Governor" Blank-0. Instead, he tried to negotiate it.
Can you imagine the uproar from the media and feminsists and the Left (sorry, redundant) if he had done "seized the day," as you put it?
We'd be hearing hysterical cries of "CONSTITUTIONAL CRISIS" and "BUSH IS SHREDDING OUR CONSTITUTION" again and again and again.
So Bush is damned if he does, and damned if he doesn't.
Yes, you're right that he should've erred on the side of saving lives. But there would've been huge political cost.
It's called principle and character. If there would be a huge political cost, I think the Dems would have borne most of it if they attacked the President for taking action. The Governor and Mayor are extremely vulnerable for their role (read lack of action and preparedness) in this crisis.