Who is promoting the inept?

The failure of the Stafford Hospital Trust and the UK Border Agency raises the question of who is promoting the bosses of these organisations, with their generous salaries and employment packages, into their positions? Surely, it is almost as bad a dereliction of duty to make these appointments as it is to actually fail in the post.
It strikes me that the system of civil service promotions supports the advancement of the mediocre by the mediocre in a push to advance the inept out of key positions. It wouldn't be so bad were in not for the fact that these people are virtually unsackable and will receive overly generous retirement packages.

One breed of people who have a proven record of leadership and could be parachuted into these high profile positions are to be found in the military. With the contraction of the armed forces there must be a surplus of men and woman above the rank of Major, say, who by their very promotion have demonstrated special qualities of leadership. There can be no better filter of ability than the military system which promotes men and woman who can be trusted with the safety of troops in difficult environments.