What was missing was common sense and presence of mind of leadership in a time of crisis. The mayor and governor were demonstrably too emotional to lead an evacuation. We saw video of a crying governor and a cussing mayor, both wringing their hands and demanding somebody (else) do something.
Time and time again throughout history, those who remained calm in a crisis are the ones who have saved lives and provided leadership.
Tens of thousands is a gross underestimate. At 50 passengers per bus, 2000 school busses could carry 100,000 people in one trip. Two or three round trips & everyone is out of NO. Oh, by the way, I am certain there were more than 2000 qualified drivers to be found in Baton Rouge, who could have taken over from anyone who felt uneasy driving a bus.
Wasn't there a story about a young man who "stole" a schoolbus and got to the Astrodome ahead of the main evacuation? Driving a school bus is not that all hard -- anyone who can drive a car can give it a whirl. Oh, there might be a fender bender or two, but since the busses were going to be lost to the storm anyway, a little bit of damage is acceptable.
They manage to find volunteer drivers on election day. Why didn't they use them?