‘But “glory” doesn’t mean “a nice knock-down argument,”’ Alice objected.

‘When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean—neither more nor less.’

The argument i see against anti-prescriptivism is that words are at their most useful when they mean something and everyone can pretty much agree on what that something is. Yes, it is annoying and pedantic and more or less pointless when someone insists that you one must say "whom" and not "who", or makes a big fuss over a verb phrases that happens to put a preposition at the end of its clause. But i think that's different from a native speaker correcting someone who's just learning a language (as a second language or a child learning their first) and has said something in a way that's nonstandard and confusing.

On that note, i do wonder how a language would evolve with no prescriptivism at all. A carefully controlled environment where nobody is allowed to tell anyone how to talk, offer suggestions, or even answer questions about the language or a statement's meaning.

I think you'll find that outside of grade school English (as a first language) classrooms people are more likely to be against prescriptivism than for it. At least, that's what i've found, but i'm more immersed in the linguistics parts of the Web than the picking-fights-for-no-reason parts.

And maybe i'm wrong about my opinion there, and i'm just being hypocritical and thinking that my level of linguistic prescriptivism is the correct one. I don't know, i'm no expert.