"Postmodernism maintains only that there can be no independent standard for determining which of many rival interpretations of an event is the true one."
Which doesn't mean it can't spot some of the stuff that's just untrue. I'll go along with Simmel and his forest, that what is exists, but exists in and as a multidimesional whole such as to put its entirity possibly out of an apprehender's reach. But that doesn't mean you can't say true and untrue things about it. And I'll go along with the position that part of good thinking and interacting is to try to see yourself in the position/pov of your interlocutor.
As for universalisms being empty, I've no problem with the universalism that everybody hates being murdered. Nor the one that says that what everyobody hates is to be avoided if possible.
Or the one that says that Terry Eagleton makes more sense than Stanley Fish and Richard Rorty.
Or the one that says how unhelpful the word 'postmodernism' can be, because it 'prevents us from making distinctions that would allow us to get a better picture of where we are and what we might do'.
Cheers, Rob.