You write, “suppose your postmodern English professor teaches you that the famous writer Wulky Wilkinsen is actually a ‘post-utopian’. What does this mean you should expect from his books? Nothing.”

I’m sympathetic to your general argument in this article, but this particular jibe is overstating your case.

There may be nothing particularly profound in the idea of ‘post-utopianism’, but it’s not meaningless. Let me see if I can persuade you.

Utopianism is the belief that an ideal society (or at least one that's much better than ours) can be constructed, for example by the application of a particular political ideology. It’s an idea that has been considered and criticized here on LessWrong. Utopian fiction explores this belief, often by portraying such an ideal society, or the process that leads to one. In utopian fiction one expects to see characters who are perfectible, conflicts resolved successfully or peacefully, and some kind of argument in favour of utopianism. Post-utopian fiction is written in reaction to this, from a skeptical or critical viewpoint about the perfectibility of people and the possibility of improving society. One expects to see irretrievably flawed characters, idealistic projects turn to failure, conflicts that are destructive and unresolved, portrayals of dystopian societies and argument against utopianism (not necessarily all of these at once, of course, but much more often than chance).

Literary categories are vague, of course, and one can argue about their boundaries, but they do make sense. H. G. Wells’ “A Modern Utopia” is a utopian novel, and Aldous Huxley’s “Brave New World” is post-utopian.