[Editor:] This article is causing quite a stir at present so I am posting it here. Read with a large grain of salt. Perhaps the problem is more that intellectuals such as Foucault and Lyotard have been misread and their warnings ignored. A current reading of Discipline and Punish provides insights into how much further things have advanced down the disciplinary track since Foucault wrote the book in 1975.
See a link below this extract to a response on The Disorder of Things blog.
Helen Pluckrose, How French “Intellectuals” Ruined The West: Postmodernism And Its Impact, Explained, Aero Magazine, 27 March 2017
Michel Foucault’s work is also centered on language and relativism although he applied this to history and culture. He called this approach “archeology” because he saw himself as “uncovering” aspects of historical culture through recorded discourses (speech which promotes or assumes a particular view). For Foucault, discourses control what can be “known” and in different periods and places, different systems of institutional power control discourses. Therefore, knowledge is a direct product of power. “In any given culture and at any given moment, there is always only one ‘episteme’ that defines the conditions of possibility of all knowledge, whether expressed in theory or silently invested in a practice.”
Furthermore, people themselves were culturally constructed. “The individual, with his identity and characteristics, is the product of a relation of power exercised over bodies, multiplicities, movements, desires, forces.” He leaves almost no room for individual agency or autonomy. As Christopher Butler says, Foucault “relies on beliefs about the inherent evil of the individual’s class position, or professional position, seen as ‘discourse’, regardless of the morality of his or her individual conduct.” He presents medieval feudalism and modern liberal democracy as equally oppressive, and advocates criticizing and attacking institutions to unmask the “political violence that has always exercised itself obscurely through them.” 
We see in Foucault the most extreme expression of cultural relativity read through structures of power in which shared humanity and individuality are almost entirely absent. Instead, people are constructed by their position in relation to dominant cultural ideas either as oppressors or oppressed. Judith Butler drew on Foucault for her foundational role in queer theory focusing on the culturally constructed nature of gender, as did Edward Said in his similar role in post-colonialism and “Orientalism” and Kimberlé Crenshaw in her development of “intersectionality” and advocacy of identity politics. We see too the equation of language with violence and coercion and the equation of reason and universal liberalism with oppression.
L.J Shepherd, In defence of the apparently indefensible (or, French ‘intellectuals’ did not ruin the West and can we please stop postie-bashing because it’s not actually terribly helpful thank you). Disorder of Things blog, April 6 2017
Foucault was profoundly concerned with medico-legal texts, government documents, and carceral practices. Derrida and Said were concerned with literature, cultural texts and film. All of them read their chosen set of empirical materials as communicative acts, asking What kinds of realities are made possible in the way that these texts claim to understand or represent political life?. It is manifestly not the case that these theorists avoided or were suspicious of ‘empirical evidence’.