Of course they don't. Security services don't have experience. People have experience. People are often incompetent. Security services have long, glorious histories of incompetence. Every day, someone with very little experience is having to make decisions.
Here's a similar example. The British armed forces have decades and decades of experience of COIN. Yet they were bloody awful at it for most of the recent Iraq and Afghanistan debacles. The fact that someone who had a job fifty years ago and was good at is it meaningless. It only matters if the person who has the job now is good at it.
Here's a similar example. The British armed forces have decades and decades of experience of COIN. Yet they were bloody awful at it for most of the recent Iraq and Afghanistan debacles. The fact that someone who had a job fifty years ago and was good at is it meaningless. It only matters if the person who has the job now is good at it.