If only we could get a significant fraction of the population to stock up for the admittedly minimal three days, which hasn't happened yet.

A three day supply in a developed area isn't too bad - it can always be stretched a day or two with only moderate discomfort. Once someone has the mindset of emergency preparedness, it is obvious that being prepared for seven, or twenty, or forty days isn't that hard to achieve - it is basically more food, water, and meds.