Excellent summaries...but you have not done much to convince one that this is better than a sharp stick in the eye!

Derrida leaves us lost to nihilism, and Foucault declares society a dystopia by construction, so...we're left in a nihilistic dystopian nightmare. Maybe I'll take the sharp stick? Or, worse yet, I'll take the analytic philosophers (how are they bad compared to this?!--dull, I can understand)?

(You also didn't address the common flaw shared by almost all such thinkers: an overestimation of how much language matters. The map, as they say, is not the terrain. The idea that language is used to convey something is mostly lost. But perhaps one should not be surprised that lovers of abstruse verbal constructions should adopt a narrative of the power and deep complexity of words in order to, um, I guess, oppress others by wielding this power?)