They're not wrong that this is A source of order, but they overlook the human tendency to form community and cooperate: this vision of theirs is about how to form societies when they are by definition all against all, a brutal struggle of nihilism and despair.
That's only one way humans can be, and it's a way that competes with the more leftist tendency to make everything about the community and cooperation.
Seems like a meta-narrative is needed that incorporates both of these positions that are held by their supporters as the ONLY position that can exist.