There have been a number of philosophers who have reveled in the dismantling of truth. I think they did so with good ethical motives, and for good philosophical reasons. I can see the sense in what they were talking about; the idea that truth is often claimed by elites in order to further certain agendas. They crowd-out alternative perspectives - particularly those of the powerless. But the undermining of truth contributed - in the weird, indirect way that philosophy contributes to the culture - to a rejection of the idea of truth as having any kind of proper meaning at all.