There's so much emphasis on hands-on activities such as making...

There's so much emphasis on hands-on activities such as making posters, small group learning with only one scribe to take down ideas, watching movie versions of books and creating PowerPoints with cut and paste with the result that grammar and spelling basics are squeezed out.
Of course this doesn't apply so much to elite English classes. They are an absolute joy. They have no problems with the English language and don't need to be pandered to so they are "engaged." Of course they love a good movie such as one on the French Revolution when they're studying William Wordsworth.
Another issue is that kids attracted to STEM subjects may not be such talented wordsmiths as those who pursue humanities.