"You rightly point to the decline of the radical labor movement as key to the crisis of Marxism, but do you think the intellectuals were/are wrong to become so self-questioning, and skeptical of, yadda yadda, master narratives?"
Did we need Derrida to warn us about master narratives? Didn't Marx do that? I mean, I certainly got that out of him way before I read Derrida.
And, yes, absolutely agreed, Chris, about the quietism of Derrida and Heidegger. I don't know Foucault well enough to comment. But remember that the "radicals" where espoused them; were fashionable radicals within academia, which isn't saying much.
Joanna