It was never actually a grammatical error. The idea that it was "in fact arose as an incorrect generalization of a personal preference expressed by a grammaria

It was never actually a grammatical error. The idea that it was "in fact arose as an incorrect generalization of a personal preference expressed by a grammarian in 1770." [1] Less has been used for countable things at least as far back as Alfred the Great in 888 CE [1], i.e. before English was English. [1] https://en.wikipedia.org/wiki/Fewer_versus_less https://en.wikipedia.org/wiki/Fewer_versus_less