My comment to Nathan Yau's
Narrow-minded Data Visualization over at FlowingData: The more that can be done to raise level of the journeyman's use of formal visualizations in public settings and their comprehension by the public at large the better off we all will be. The level of functional illiteracy and innumeracy in the USA is too high to offer anything more than the most prescriptive of rules and examples -- ie, "use visualization X when you need to convey data Y".