There should be a middleground between "The dictionary is law" and "Any native speaker can redefine a language".

At the very least the direct consequence of

>If the grammar rules you learned in school disagree with (any!) native speaker, the rules are wrong.

is that every language has as many dialects as speakers.

Imo dictionaries are descriptive rather than prescriptive not because it is impossible to have prescriptive definitions or grammar, it is just that dictionaries do not even try; usually they just list common usage of words.

> is that every language has as many dialects as speakers.

This is actually treated as linguistic fact, although we call them "idiolects" when we're talking about that level of granularity.

> not because it is impossible to have prescriptive definitions or grammar, it is just that dictionaries do not even try

They don't try because the field of linguistics has arrived at the conclusion that the role of the linguist is to document what is, not to prescribe what should be. They arrived at that conclusion by studying languages and discovering that they are far, far more messy than prescriptivists had hitherto believed.

The only role that prescriptivism has these days among serious academics is an acknowledgement that while all forms of language are well-structured according to well-defined grammatical rules, cultures assign value judgements to certain forms of speech and so it's valuable to learn your culture's value judgements and learn to speak and write in a way that earns you credibility in your culture.

But even this looks very different than the prescriptivism of old, because what forms of speech and writing get creds vary dramatically from generation to generation, place to place, and even context to context. Learning the grammatical rules taught in traditional schools will not help you fit in on modern social media.

But even knowing all of this, prescriptivism was beaten into many of us growing up, so some internal cringe is unavoidable.

For ex still cringe at people saying “anyways,” even though I know it’s a losing and pointless battle.

Not sure what the biggest driver is - being shamed while growing up, or just latent pedantry.

I have no issue with the linguists deciding that their discipline is descriptive rather than normative. Most scientific endeavours are.

My issue is with the claim that there is no sense in which a native speaker can make a grammar error. Maybe we should call them "idiolect incongrueces" I do not care.

In my language there is a verb tense that is often misused, I often misuse it and I can hear the resulting sentence I say feel wrong. That is a grammar mistake the same way missing a note in a song is a mistake.

If linguists want to work towards reducing the stigma issues of standardized grammars I commend them and wish them good luck. But that is different from saying that grammar mistake do no exist.

> If the grammar rules you learned in school disagree with (any!) native speaker, the rules are wrong.

I understand the sentiment of "the language is defined by its speakers", but this statement seems a bit overblown. According to that logic, it is literally impossible for someone to be incorrect about the meaning of a word.

> it is literally impossible for someone to be incorrect about the meaning of a word.

Yeah, it's important to frame it in terms of idiolects and dialects—any given speaker has an idiolect, and that idiolect is worth describing and documenting uncritically. But that speaker also benefits from speaking a shared dialect with other speakers, and it's valuable for that speaker to be on the same page with other speakers of their dialect about definitions.

I think what OP is getting at is that it's not the role of linguistics to assign a value judgement to a given usage—there are merely benefits that speakers can derive from better understanding the dialects that they use in daily life.