[stjohnswarts]

They haven't, it's a clear exaggeration, and lacks any substance at all.

[ncmncm]

Which is not to say he was right about human language acquisition. (He wasn't.)

But the three grammar classes were correct, and are still in use. They were later found to match work done 2500 years ago, in India.

Being wrong in science, particularly biology, is not a crime, nor, usually, even a shame.