>>I suggest that the decline of journalism began when schools stopped teaching sentence-diagramming.>>
Absolutely agreed! I once asked a teacher why they eliminated the diagraming and was told, “Oh, that’s so old fashioned.”
When my kids ran into trouble with their sentence structure I taught each of them the diagramming method. They all improved dramatically.
I suspect that some educators introduce “new” methods of teaching only to appear to be ahead of the others and get promotions.
Many students, especially boys, respond well to the visual-structure, spatial-relations nature of the traditional diagramming process. It lights up all different parts of their brains, so to speak ... and they can also have fun moving the phrases and clauses around to end up with things like having a c-section on Facebook ;-).
Keep in mind that a vast majority of Ed majors dropped out of the Yogic Meditation and Macrame programs due the overly stringent course requirements.