At afternoon tea today, one of my colleagues raised the point that, particularly in Europe, the prefix neo- is automatically taken to be pejorative, with neo-liberal as the obvious illustration. It struck us that the corresponding, positively weighted prefix is post- , as in post-Keynesian, post-Communist and so on. [1]
My thought on this is it reflects an underlying progressivist assumption, shared even by many people who would reject explicit claims about historical progress. Given this assumption “post-X” is good, since it represents an advance on X, while “neo-X” is bad since it represents a reversion to X, implying the existence of some Y which must be post-X.
Feel free to provide counterexamples, contrary explanations and so on
fn1. The exception that proves the rule is post-modern, which is now often pejorative, but was entirely positive when it was coined.

