More from Robert Harrell:
If you follow the history of the teaching of languages, a number of practices become logical – even if misguided.
Up until the early modern period, Latin and Greek were taught as means of communication. When those languages were superseded by French (and later English) as the medium of international communication, universities and schools had to create a rationale for continuing to teach them. Thus arose both the idea that learning a (classical) language “exercises the mind” and the grammar syllabus.