The Right used to abhor postmodernism, and were properly mocked by the Left whenever they whinged about it. Now the Right have embraced postmodernism, and the Left have no idea how to respond.
That happened back with George W. Bush ironically and really ended it for the postmodernist side. There was one interesting article about it. http://clubtroppo.com.au/2012/02/22/george-bush-bruno-latour... Being disengaged with reality because it doesn't say what you want it to isn't a good thing but some delusions are more harmful than others.
The PoMo "side" is not exactly the Leftist side, however. If reformed PoMo enthusiasts expect all this to go away now that they've seen the error of their ways, they will be disappointed. The discourse from 4chan etc is not only a reaction to a particular political circumstance, but also to the experience of real people in economic, advertising, media, social, etc arenas. The channers have found something that empowers them to speak back to dominant narratives that exclude them, and they're not going to give it up just because e.g. Latour has changed his mind.