> "People" as a whole have not even heard about mixing instructions and data, and certainly not the reasons why it is not a good idea.

Because it's not a concept in the real world. Physical reality has no such separation, and neither do human minds.

Tell people you're discussing a board game or some sport, then they'll understand - other than bureaucracy (scary!) and school (traumatic!), that's the one kind of artificial system with rules affording for code/data separation that general population has most experience dealing with.