Interesting article, but surely confuses symptoms with causes. I don't see French intellectuals as a cause of various intellectual trends, but as part of a cycle. You can cite for example Freud and Nietzsche as skeptics about various things, e.g. religion. Freud has an interesting passage where he talks about the 'dethroning' of the human ego, via Copernicus, Darwin, and of course, himself.
NS right about a melange, nice word, anyway. You could trace postmodernism to the current of skepticism in philosophy, or I should say, various currents of skepticism. How far do you trace this? Francis Bacon? Hume? Pyrrhonism? Dunno.