Nihilism (which is derived through rationality) and the relativism it creates (which is also rational) paradoxically opens up an enormous space for the irrational. The relativism inherent in nihilism that declares that everything is possible, therefore authorizing any opinion from a subjective point of view, is also stating that the irrational is valid as well, and while this opens doors for creative thinking it also drags the nihilist standpoint down into an abysmal hole where rationality drowns in relativity.
This is important because we exist in fundamentally nihilistic societies that seem on the surface to be driven by rationality, but are in fact deeply irrational. Nationalism, for example, is absurd if considered from the logic of human reason because all nationalism segregate humanity and national pride is an anti-humanist concept. Nevertheless, nationalisms, and their supposedly more benevolent sisters that are called patriotisms, have thrived in the modern, nihilistic world, despite the horrors that these concepts have procured (just think of wars and ethnic cleansings). Likewise, in the very midst of our contemporary world, we see a resurgence of logically absurd religious sentiment everywhere. While we applaud the technological advances of our civilisation, we also give credence to the mythological fantasies promoted by religious groups who still wield enormous power in our societies. As such, we live in a heterotopia: the world we think we live in, does not really exist at all.
Relativism, of course, is a synonym of scepticism that operates in reverse gear, taking the sceptical idea that everything is questionable, it turns it on its head and says that all things are just as questionable as each other and this, therefore gives them the same degree of validity: ergo, everything is valid.
So, from nothing is valid, we now get everything is valid, and this makes everyone happy in the feeling of freedom they have in order to be as irrational and carry out any illogical or down-right stupid act they feel like.
Yes, we still have the System to save us from anarchy, and the System can always use the extremisms of the logically absurd groups it associates with to enforce controls that would be impossible in a truly rational society rooted in holistic purposes and the central idea of humanity rather than floating aimlessly in an ocean of nihilism.