I believe there is a disconnect between writing as it is taught in secondary education and what happens in the college composition classroom.
I know I am not the only instructor who believes that the early part of the semester (and beyond) involves a kind of “deprogramming” of some beliefs and habits that have been inculcated prior to students arriving in college.
As a rule (to which there are exceptions), many students come armed with a series of writing “rules” that are meant to be followed, or else. Essays are five paragraphs long, and should never contain “I,” “you,” or “we.” Some have been told that each paragraph should be limited to 5 (or 7 or 9) sentences, and that all concluding paragraphs start with “In conclusion.”