When the costs of your mistakes are paid for by others there is no incentive to learn.
And in practically all institutions those who point out problems become the problem...it is very career-limiting to notice the errors of your superiors...or their mentors in the generation preceding them.
Afghanistan has shown exactly how the us can't manage an army composed of soldiers of a different country/ethnicity/religion
USG is not very good at learning from its own mistakes.
When the costs of your mistakes are paid for by others there is no incentive to learn.
And in practically all institutions those who point out problems become the problem...it is very career-limiting to notice the errors of your superiors...or their mentors in the generation preceding them.