Whether you drink soda or pop; whether you order a submarine, a hoagy, a grinder or a po' boy; whether your pronunciation makes any kind of distinction with marry, merry and Mary — all this will mark you somewhere, sometime as an auslander, not One Of Us.
There is always something in language beyond the literal meaning of the words, something social, something understood (or half-understood) implicitly. One of those unspoken understandings is whether or not you belong in the group.
When I went off to college in 1969 to be an English major, the grand old Eliotan historico-critical-literary approach was not yet desiccated. But there were other options as well. The twerp under whom I ill-advisedly spent a term studying Shakespeare remarked one day, "Now I don't want to give you the straight Freud-Jones interpretation of Hamlet," to which a classmate seated next to me muttered, "No, you just want to dance around it for an hour." There were also Jungian and Horneyan options in the department. Feminism was on the upswing. There was still some juice in Marxist interpretations as well, and distantly, from France, strange new emanations were registering.
The fullness of semiology, structuralism and post-structuralism sweeping over the academy showed that anything, anything at all, could be run through the mill and deconstructed: comic books as well as the canonical writers, pop songs, television commercials, restaurant menus. Anything could be anatomized, its concealed significances exposed to light and air.
To be respectable, an academic discipline must display a terminology that the layperson has difficulty understanding. Mastering the lingo demonstrates that one is among the elect. The other disciplines must envy physics above all: Not only does it have concepts that are hard to understand, but also it requires a grasp of arcane mathematics. Mathematics is the perfect marker; it shuts out nearly everyone, and it is actually essential and of use. Other disciplines — I won't say education, but you can probably supply some — require the invention of obscurantist terms to conceal what would otherwise appear straightforward or even obvious.
The complication, and the thing that led Mr. Liberman to pick up on the snide tone in the "grinder" remark, is that the jargon, the machinery may well express some valuable concept or insight, but it might equally well conceal that the writer is unoriginal, misguided or befuddled. It can eat away at an afternoon in a carrel to determine that the article in the learned journal before you is, well, stupid. It established that the writer is in the club and helped get the writer promotion or tenure, but it is an utter waste of your limited time on this side of the ground.
There's the hazard. Whatever you say or write has multiple meanings. Sometimes, and not just in the academy, you have to detect that the secondary meaning has overwhelmed the primary.