LOL! I once assigned one of those paragraph-long sentences from Robinson Crusoe to a kid to be diagrammed, and he did it! LOL
I love diagramming. I find it very useful. In fact, in teaching things like dependent clauses and things like that, I never really “got” it until I had a teacher who taught me to diagram, and then I understood. I’m a visual learner, though, so it just makes sense to me. But I taught my kids to diagram, and it’s really helped, I think. Now I can just tell them, when I see a sentence they’ve written that has poor use of clauses, or lacks agreement, or has fuzzy adjectives or something, “Go diagram that one” and they come back and can “fix” it once they see the problem.
Plus diagramming is kind of like a puzzle–it’s a lot more interesting, IMO, to diagram things than to just copy them out endlessly and label the parts of speech and clauses over them. Give me a nice diagram any day. 🙂