The real reason p=none persists is because people would rather err on the side of email being delivered that is actually junk than having a miss of legitimate mail. (This also the reason for so many soft failure entries in SPF records.)
When I learned about this during the post-mortem I was incensed, to say the least. Email mgmt is part of a professional’s job, for better or worse. Accountability for that doesn’t suddenly evaporate because of a scenario like this. I don’t practice zero inbox for fun. I do it for my sanity and effectiveness. Technology can’t magically solve every problem.