Steven Pinker writes in The Language Instinct, pp. 370 to 373:
(after describing how ludicrous someone would sound complaining that the song of the humpback whale contains an ’error’ or the chickadees are building their nests ’wrong’ and monkeys’ cries have been in a state of degeneration for decades, he contrasts that with how seriously we take similar complaints about human language….)
“But for human language, most people think that the same pronouncements not only are meaningful but are cause for alarm. Johnny can’t construct a grammatical sentence. As educational standards declineand pop culture disseminates the inarticulate ravings and unintelligible patois of surfers, jocks, and valley girls, we are turning into a nation of functional illiterates: misusing ’hopefully’, confusing lie and lay, treating data as a singular noun, letting our participles dangle. English itself will steadily decay unless we get back to basics and start to respect our language again.
To a linguist or psycholinguist, of course, language is like the song of the humpback whale. The way to determine whether a construction is ’grammatical’ is to find people who speak the language and ask them. So when peopole are accused of speaking ’ungrammatically’ in their own language, or of consistently violating a ’rule’, there must be some different sense of ’grammatical’ and ’rule’ in the air….. One can choose to obsess over prescriptive rules, but they have no more to do with human language than the criteria for judging cats at a cat show have to do with mammalian biology.
[He then talks about who establishes the prescriptive rules and where the term ’language maven’ came from and goes on to write]
To whom I say: Maven, shmaven! Kibbitzers and nudniks is more like it. For here are the remarkable facts. Most of the prescriptive rules of the language mavens make no sense on any level. They are bits of folklore that originated for screwball reasons several hundred years ago and have perpetuated themselves ever since. . For as long as they have existed, speakers have flouted them, spawning identical complaints about the imminent decline fo the language century after century. All the best writers in English at all periods, including Shakespeare and most of the mavens themselves, have been among the flagrant flouters. The rules conform neither to logic onor to tradition, and if they were ever followed they would force writers into fuzzzy, clumsy, wordy, ambiguous, incomprehensible prose, in which certain thoughs are not expressible at all. Indeed, most of the “ignorant erros” these rules are supposed to correct display an elegant logic and an acute sensitivity to the grammatical texture of the language, to which the mavens are oblivious.”
He then talks about the period in English history when these rules were concocted. Where he describes the current crop of mavens, he lays out their claim for wanting to regulate the language: it is to “maximize its clarity, logic, consistency, conciseness, elegance, continuity, precision, stability, integrity, and expressive range. (Some of them go further and say that they are actually safeguarding the ability to think clearly and logically. This radical Whorfianism is common among languages pundits, not surprisingly; who woul dsettle for being a schoolmarm when one can be an upholder of rationality itself?)”
The whole chapter pp 370 to 403 is fun to read.