Postmodern philosophy eventually comes to the conclusion that all meanings are tentative because nothing is absolute; categories break down, and meaning dissolves.
But what if the absolute, the pure, is not a factual or intellectual quality and is instead an aesthetic one? By not being factual, I mean that the pure is a matter of opinion, inherently unverifiable, and profoundly non-literal; by aesthetic, I mean that it is subject to interpretation, and is a question of mood and style as much as anything else. A field of snow could then be absolutely, perfectly, purely white despite footsteps, bird droppings, and whatever else; there need be no authoritarian, ideological clearing of that snowfield to guarantee its purity.
That would explain the primacy of cultural criticism over philosophy, for one thing. It could rescue purity from its fascist, racist, and authoritarian leanings, as it would be definitionally beyond proof or demonstration. It would leave the “pure” intact and unreachable — where it belongs.