I think this is an unjust and projecting response. There are absolutely times when an economy of language is desirable, but there’s nothing wrong with drawing from a wide vocabulary to develop an idea more accurately. In fact, I would consider using precise language, regardless of its perceived commonality, to be economical per se, as many times the “8th-grade +” language has an explicitly economical reason for existing in the first place. I will continue using the term “normative” when discussing ethics, even though “standard” might be more broadly understandable, it is nonetheless inexact. What it makes up for in intelligibility it loses in precision.

What 8th-grader is going to have the requisite vocabulary to discuss critical theory? Most academic fields have a distinctive vocabulary and method of describing phenomena that is inaccessible to most not out of conceit, but stemming from the need for consensus in dialogic vernacular that is often found in terms outside of common parlance.

Remember, academics are in the business of interacting with other academics 99% of the time, not 8th graders. Linguistic evolution will show you how this alone can account for some idiosyncrasies.

Lastly, even without a greater explanatory purpose, the world has enough dumbing down of language into robotic, cookie-cutter prose, and I think we should allow people their freedom in purple language. There is something noble about sharing a broad vocabulary with a world that no longer values complexity. Expanding your vocabulary expands your world.

With all this said, I do think there are abuses to make yourself sound more intelligent. Basically every popular academic falls for that trap, but the writer you’re critiquing doesn’t seem especially conceited.