Because Man is existentially flawed he is incompetent to think or act in accord with moral action. 

Incompetence is directly tied to an existential corruption. All humanity is guilty of some cosmic sin (e.g. Pervasive Depravity) and therefore is preemptively guilty of the highest cosmic crime, which disqualifies every self defense.

Because Man is existentially incompetent to know or do good and is preemptively guilty in any self-appointed action, therefore Man must have GOOD dictated to him by an elite group--somehow--exempt from the guilt and incompetence. 

Ambition is always portrayed as the individual run amuck, devouring whatever and whomever he chooses therefore all individual desire to improve ones self is default evidence of the evils of individuality. Man can have zero ambition aka interest in self improvement.  

Man's moral corruption is illustrated by his independence therefore he must subordinate himself to the group, the tribe, the society to achieve moral absolution.