Because at some point succinctness morphs into incomprehensibility. Every academic pursuit has its own jargon, of course, but social scientists have a harder time of it because there is less agreement about the basic axioms at play. (To put it another way, when physicists start talking about Hilbert spaces, it easy for the layperson's eyes to glaze over, but everyone who studies quantum mechanics agree what Hilbert spaces mean. When Butler and her peers start discussing concepts, it is easy to disagree in small but significant ways about what the most basic of concepts are.)
I really do not think that Butler is doing this here, but the discussion to date reminds me of a Calvin and Hobbes cartoon from back in the day:
Calvin: "I used to hate writing assignments, but now I enjoy them. I realized that the purpose of writing is to inflate weak ideas, obscure poor reasoning, and inhibit clarity. With a little practice, writing can be an intimidating and impenetrable fog! Want to see my book report?"
Hobbes: "The Dynamics of Interbeing and Monological Imperatives in _Dick and Jane_: A Study in Psychic Transrelational Gender Modes."
Calvin: "Academia, here I come!"
--tim francis-wright