Cover Up

It is the nature of large organizations -- whether they're the Catholic Church or General Motors or the United States Government -- to be closed mouthed about their operations. Every large organization has it secrets and will go to extraordinary lengths to protect those secrets when forced to by outsiders. The Government hides things -- and uses valuable resources to hide things -- that would produce little or no scandal if they were revealed to the general public. Any criticism, any question that comes from someone not associated with the organization is routinely perceived as a threat and the immediate response to any threat is to circle the wagons.

No thought process whatsoever is involved in the above scenario; it's all reflexive behavior. This is why organizations with divergent personalities, political  outlooks, and cultural goals all act the same under pressure. This is why otherwise honorable people will move heaven and earth to cover up actions or behaviors that might or might not be subject to public censure. The larger and more powerful or influential a group grows, the more paranoid and more secretive its membership becomes. Most cover-ups aren't planned, they just kind of happen.