Writing education pedagogy of the last 30 years has been completely devoted to fostering "self-expression," which is limited when students have to worry about things like proper spelling, usage, and grammar.
Rather than make children feel bad about themselves, teachers were instructed to ignore those standards and focus on the child's "narrative."
When I was a junior in high school, (late 80's, California) my Honors English teacher became highly irritated with the quality of our writing. He walked to the chalkboard, wrote out a full sentence and attempted to walk us through the process of diagramming it. It took him about 30 seconds to realize NONE of us had any idea what he was doing.
Instead of chucking the next novel we were supposed to read and focusing on diagramming sentences, he gave up. He never mentioned it again.
He was really a great teacher in general, but very close to retirement by that point. I think he'd been beaten down by the system.