Lestrange

In Spectres de Marx Derrida describes a political movement that gets back to the roots of Marxism (and away from the supposed bastardization of Marxism that Leninism/Stalinism represented), so to speak, with a new deconstructionist coalition that continues in the "spirit of Marxism". The book was a crystalization of views he had developed over the preceding decades, when he had done the most to develop postmodernism.

While postmodernism differs from Marxism in many ways, and while its progenitors were inspired by and attempted to build on top of Marxism to different degrees, it certainly comes from the same intellectual tradition of radicalism, and advocacy of overthrowing power structures, as Marxism, and was formulated mostly by intellectuals that accepted several of the basic suppositions of Marxism.

This shouldn't be surprising, considering how prevalent Marxism was among French intellectuals in the postwar period.

As for whether Marxism has any redeeming value, I'd argue that even if it did, the recklessness of its attacks on the capital owning class, in concepts such as surplus value, exclude it as a perspective worthy of being given that level of respect. Marxism crosses a line in human relations that is hard to come back from, and hard to build a humanistic society on top of.

The giants of postmodernism, like Jacques Derrida and Jean-Paul Sartre, were fanatically Marxist before they became postmodernists. They themselves described their philosophies as evolutions of Marxism. Derrida for his part described his outlook as carrying on the spirit of Marxism.

The philosophy very openly calls for deconstruction of all existing values and power structures, and a radical rejection of what the modernist interpreted as reason.

I think you are deliberately downplaying this element of postmodernist philosophy and I don't think you're doing the discussion any favors by casting your opponents as bigots.