Good point about fresh food. Also, a lot of folk aren't used to having to cook from scratch, as opposed to opening boxes and cans and warming up the contents or tucking something from the freezer case into the microwave or grabbing something from a take-out window or a grocery store deli. Thus, A) they probably freak at the prospect of actually cooking, and B) 12 weeks worth of fresh and prepared foods would take up much more space than 12 weeks worth of raw ingredients. Finally, people probably are thinking in terms of the variety of their regular diet, not in terms of "what will keep me alive for 3 months", and 12 weeks worth of foods for a varied diet would be more space-intensive than the sort of basic life-sustaining foods I mentioned.

We have the bulk supplies (bag-o-rice, bag-o-navy-beans, bag-o-pinto-beans, bag-o-rolled-oats, bag-o-masa, bag-o-pearl-barley), and then we have the smaller quantities: 5 # of dried split peas, ditto kidney beans, ditto soybeans, cans of corned beef and tuna, home-canned jams and pickles and chutneys, a few cans of tomato products, a few jars of applesauce, a few boxes of rice milk and soy milk. The fact that we have no choice but to cook from scratch actually makes it very easy to keep plenty of food on hand. We also have a good camp stove and a sheltered place to use it outdoors, plus a gas stove in the kitchen to start with. So food's pretty simple for us. Some of the other preparedness things, not so much.