There were mistakes made all around on this one, plenty of blame to spread around starting with the welfare state facilitating a class of people unable and unwilling to look after themselves, having no significant civil defense programs in place, etc. The time to mitigate these things is before they occur, P.P.P.P.P.P.
Bush administration actions that contributed to the poor response to this disaster include;
Cutting funding for the Army corps of engineers repair project on the NO levees.
Appointing an inexperienced, ineffectual FEMA director with good connections.
Incorporating FEMA into homeland security without maintaining its capabilities in non-terrorist related events such as this. The people calling the shots at FEMA were focused on other things and dropped the ball, that's the real story on the federal portion of this failure, homeland security got its first big test and failed miserably.
Taking too much vacation time, I know he can do his job from the ranch but the federal job doesn't seem to get done while he's on vacation, there's a pattern that's getting tough to defend at this point.
And lets face it, there wasn't enough national guard resources in the region to deal with an event of this magnitude, for the war or against it doesn't matter, we need the guard for these things and we need them at full strength here at home. There are different branches of service for a reason.
The local government completely blew the evac., didn't get information to the feds effectively, and most disappointing at all they didn't follow their own plans for such an event, which led to all sorts of problems that didn't have to occur.
But the biggest mistake of all was made by the million or so people who decided to live below sea level in an area vulnerable to hurricanes, it was going to happen, it was going to be bad, no matter what anybody did. Blame God if you have to blame somebody.
BUT, when FEMA doesn't know about 30,000 people without water four days into the event, and doesn't get water to them for another two, it's clear that agency dropped the ball, how hard is it to get an airlift organized?
The REASON everybody is pointing fingers however is that government cannot do what it claims to do, which is to protect the citizen. The citizenry is angry because it's pretty hard to justify all the taxation, regulation and interference in peoples lives in light of this fact, and anger that should have been there all along is now being directed at government by those that haven't yet come to the realization that it cannot EVER protect them effectively, no matter how high the taxes or how good the leadership.
So that's WHY.