Obviously, not all academics write like this. Not by far. It's the hallmark of various followers of postmodernists like Derrida and Lacan. Particularly favored by far-left academics in departments of gender studies, multicultural studies, women's studies, etc.

Multiculturalism is a wonderful thing, but not the brand that these frauds sell.

You can read a pretty devastating critique of these pseudo-scholars in the book Fashionable Nonsense, which describes how two physicists made up a completely bullshit paper, full of utter nonsense, had it accepted for publication in one of the leading postmodernist journals of the time, and confronted a fierce but intellectually empty counterattack by postmodernism's supporters(this was in the 90s) [1].

1. http://www.amazon.com/Fashionable-Nonsense-Postmodern-Intell...

The disagreement is not between literary theorists and sciencey types

Sometimes it is! (http://www.amazon.com/Fashionable-Nonsense-Postmodern-Intell...)