In recent years, The New Yorker's coverage of the "descriptivist vs. prescriptivist" divide in English usage has been, shall we say, problematic. In 2012, we had Joan Acocella's "The English Wars," critiqued by Mark Liberman here and here. That was followed up by Ryan Bloom's Page-Turner piece, "Inescapably, You're Judged By Language," which I tackled in "The New Yorker vs. the descriptivist specter."
In Acocella's piece, Steven Pinker is set up as a descriptivist strawman on the basis of a wildly off-the-mark reading of an essay he contributed to the fifth edition of the American Heritage Dictionary. (Pinker serves as chair of the AHD Usage Panel.) He ably defended himself in a subsequent letter to the editor and at more length in a piece for Slate, "False Fronts in the Language Wars." Now another New Yorker critic, Nathan Heller, makes a mess of things in his review of Pinker's book The Sense of Style.
Heller accuses Pinker of "sentences [that] do not add up" and says that his usage suggestions "actually make the language more confused." But I found Heller's piece to be deeply confused, even while it purports to elevate clarity above all else. One source of confusion is a telling typo in a quote from Pinker:
Pinker did not write that "any prescriptive rules originated for screwball reasons." The correct quote is "many prescriptive rules originated for screwball reasons." (In a delicious irony, this sentence first appeared in Pinker's Slate piece on The New Yorker's previous misconstrual of his work.) As misquoted, the reader might think that Pinker, as one of those loosey-goosey descriptivists, is opposed to "any" prescriptive rule, since all that matters is "any way a lot of people use the language." Once again we see the false dichotomy outlined by Geoff Pullum in his post, "'Everything is correct' versus 'nothing is relevant'" — just the sort of dichotomy that Pinker's book seeks to transcend.
[Update: the "(m)any" typo has now been fixed in the online version.]
Heller's counterargument is that what counts as "correct English" (conflating style, usage, and grammar under one banner) is "correct" because it is somehow naturally better: more logical, more clear-thinking, more consistent:
It’s for grammatical consistency, not beauty or gentilesse, for example, that correct English has us say “It was he” instead of “It was him.” Pinker calls this offense “a schoolteacher rule” that is “a product of the usual three confusions: English with Latin, informal style with incorrect grammar, and syntax with semantics.” He’s done crucial research on language acquisition, and he offers an admirable account of syntax in his book, but it is unclear what he’s talking about here. As he knows, the nominative and accusative cases are the reason that we don’t say gibberish like “Her gave it to he and then sat by we here!” No idea is more basic to English syntax and grammar. In the phrase “It was he,” “it” and “he” are the same thing: they’re both the subject, and thus nominative. This is not “Latin.” (Our modern cases had their roots in tribal Germanic.)
But here's the thing. No native speaker would ever say "Her gave it to he and then sat by we here," but I'd wager that the vast majority of speakers (and even Heller himself when he's not monitoring himself for correct usage and grammatical consistency) would prefer "It was him" to "It was he." Accepting "It was him" as completely natural, idiomatic English does not require heading down a slippery slope where the nominative vs. accusative distinction is lost entirely. But if Heller would like to valorize "grammatical consistency" above all else, he's welcome to insist on "It was he," "It is I," etc., which, as Geoff Pullum noted, "is an extremely formal usage, encouraged by really old-fashioned prescriptivists but not seriously used these days by anyone except the unbearably affected." The argument that a pronoun-as-predicate must take the nominative case might be logically appealing, but as James Harbeck wrote on the topic, "language is not math."
The same is true of “who” and “whom,” another nominative-accusative pair to which Pinker objects, sort of. He writes, “The best advice to writers is to calibrate their use of ‘whom’ to the complexity of the construction and the degree of formality they desire.” Yet who wants to undertake that calibration all the time? The glorious thing about the “who” and “whom” distinction is that it’s simple.
Ah yes, that gloriously simple distinction between "who" and "whom"! I guess all of those native (and non-native) speakers who feel anxious about the proper use of "who(m)" are just too thick-headed to appreciate something so simple. Let's just consider one example of how the selection of "who" vs. "whom" in standard English is far from straightforward. Here's a sentence I found in The New Yorker, written by, you guessed it, Nathan Heller:
But what about Sir Isaac Newton, whom some contend was autistic?
("Little Strangers," 11/19/12)
Simple, right? Just figure out whether the noun replaced by "who(m)" is a subject or object and choose accordingly. In this case, the "who(m)" fills the slot in the clause "Some contend (that) ___ was autistic." It's the subject of the embedded relative clause "___ was autistic," but it's tempting to use "whom" in sentences like this, if you're the type of person looking to use "whom" in the first place. (Whether Heller or his editors should be held responsible for the "whom" here, I cannot say.) Arnold Zwicky has written at length about the temptation to use "whom" in this sort of construction, e.g., "Whom shall I say [ ___ is calling ]?"
Appeals to rationalism have long been a hallmark of the prescriptivist mindset. But the messy details of actual language use will inevitably undermine that rationalism. For those who care to delve deep, it's gloriously complex, not gloriously simple.
[Update, 12/2: On his blog, Arnold Zwicky dives more deeply into the flaws of Heller's piece.]