> The language you speak is the result of thousands of years of casual communication by billions of human beings.

Disagree. The language I speak didn't exist 800 years ago. The Anglo-saxons wouldn't have understood me, and I wouldn't have understood them.

And there were barely a billion human beings just 800 years ago - forget about thousands of years.

I didn't mention "prescriptivism", although it's obviously the opposite of descriptivism.

I thiink you mistake "prescriptivism" for a sort of law-making,like grammar-nazis. I mean something more like a general acceptance that words do have particular meanings, and that it's possible to be wrong about the meaning or use of a word.