What highschool "literature" class isn't heavy with writing exercises? I've never heard of an English class where you just read (except in college, where you're expected to also be taking dedicated writing classes.)
Why do you assume that the class mentioned doesn't include writing?
I'd assume they were writing about the graphic novels. But I also assume they were discussing the themes in class and we took multiple choice tests about things we read. It wasn't always writing. In current times, this would especially be the case if the school system had an initiative to cut down on the sheer workload of homework. (Which I approve of, most teens don't need hours of homework on top of school)
What you don't learn to write are actual freaking novels, just like they aren't going to teach you how to illustrate and write a graphic novel in most high school classes. You write essays, research papers, and things like that. Not entire novels.
I responded to a (your) comment claiming that highschool English classes are consumption-mode literature classes.
> Kids don't learn to write novels in literature class either - you've missed the point of such classes.
> Literature classes are consumption courses, too, and lead a few to develop a lifelong reading (and consumption) habit, btw.
Kids don't write full novels in those classes because the timeframes involved couldn't possibly permit it, but nevertheless half the time in those courses is dedicated to getting students to write short stories, poetry, (not merely essays!) At the highschool level the courses are about writing as much if not more than about consuming literature.