People always talk about the simplicity of the plan, but I am staggered at how many things had to go right not just for one plane to hit the tower, but for two planes and then a third into a fucking pentagon! Think about all the things that had to go right not just on the day with 19 hi-jackers but also in the years leading up to it with everyone else involved and the flying lessons etc.
Aided to a minor degree by the dick-swinging going on in America's 18 security agencies.
It is frightening how badly their agencies seem to work together
The problem with political appointments is that the people you appoint may be political. The USA hasn’t operated a meritocracy for a very long time.
Most (not all) of their departments of state are headed by presidential appointments who either resign or get fired by a new president. While that seems weird to us, it does avoid the political issue of previous appointees not properly implementing the president's policies (or at least removes that as an excuse). It also sort of makes sense in that the president is the Head of the Civil Service, and they bring their team with them.
Presidents still normally attempt to find competence and experience on their side of the aisle, particularly in the law and order positions (eg FBI, CIA, NSA, armed forces, Attorney-General). The civil service that actually does the work is also permanent public servants like here - in theory the president can fire almost any of them, but in practice they haven't got time for that on a large scale. Not that it happened then, but a modern issue is also the furlough due to scraps over the budget. Furlough = unpaid leave while the civil service waits for Congress to approve a budget. Not surprisingly, that causes talent holes as quality public servants can't be bothered with that, and move on.