One basic point about moderates is that you need them to have anything of value maintained or created. Even the largest armies can't grow beyond 10% of the population for long. Having a heretek forge building tanks and starships requires social law enforcement even if it isn't actually written. (two examples, Q’Sal with their no war policy or to jump systems, the drow with their specific rules on what you have to do to kill a rival)
You could imagine a khorne society as a samurai society gone crazy. The warriors are the ones "blessed" and they get to have the weapons and kill. Meanwhile the majority of the population is peasants busy farming to support the warriors.
A society where everyone is embracing chaos is one where everyone starves due to lack of food.