No question that some do and will always fail to read the instructions -- but IMO, solution for that is not in wetware but in software: a daemon to read the draft/preview and squawk loudly if neither a <p> nor <c> tag is found... where "squawk loudly" means "refuse to submit/post the node."

But that's merely an aside -- my on-topic mindset is that while an advisory such as the OP will be ignored by some, others may heed the guidance.