If you know your family would not eat something, unless they were starving, why would you waste $$$ stocking up on that item?
This is my main reason for stocking what we normally eat. My husband hates tuna. No point in wasting money buying the stuff.
We are very much in the 'store what you eat' camp. In fact, I think it is more a matter of
learning to eat what you store, rather than storing only what you currently eat. Occasionally, this has meant adjusting our diet, and / or learning a new way to cook. If you actually eat what you store, you know everyone in your family will have comforting food they like and will eat without a fight. You will probably end up eating healthier if you start incorporating storage food into your diet now, as it is usually low-fat and full of nutrients and fiber. Also, it is a cheap way to eat. And a cheap way to store extra food. Bulk legumes and grains don't cost much, and ingredients are always cheaper to buy than end-products.
If you don't know how to cook with whole wheat and dried beans, you probably aren't going to learn very easily after things go stupid, unless the crisis happens to be one of unemployment. You will waste food and fuel trying to figure out what to do with the hundreds of pounds of whatever you stocked. In addition, lots of long-term storage food has different textures and / or cooking requirements from their canned or store-bought comparison, and you might find your husband / wife / kids will absolutely refuse to touch crunchy beans or dense bread or mushy rehydrated blueberries.
In answer to the original post, for long-term storage, we keep whole wheat, brown and white rice, several varieties of beans (navy, black, kidney, romano, etc), chickpeas, barley, split peas, lentils, oatmeal, a variety of dehydrated and freeze-dried fruit and vegetables, instant mashed potatoes, canned fruit and vegetables (home-made and store-bought), canned meat (going to get into canning our own shortly), olive and vegetable oils, lard, powdered milk, sugar, honey, pasta and pasta sauce, and a lot of 'seasoning' type stuff, like soy sauce, chili paste, cocoa, soup mixes, herbs and spices, salt, and canned sauces. While it does not really count as long-term storage, except in periods of unemployment, we go to you-pick farms and farmer's markets, and freeze our year's worth of local, organic corn, raspberries, strawberries, rhubarb, wax beans, peas, etc. We also freeze butter and some yogurt (for a starter). In addition, we have a cold room where we keep a lot of root veggies, like onions, carrots, beets, turnips, and so on. The root veggies will keep for months like that - we threw out the last of last year's beets (stored from September) in June of this year.
While we do not eat all of the stuff from our storage every day, or even every month, we have sampled and taste-tested and learned to cook with the things we keep in bulk. We make our own bread from the wheat, and use the beans and lentils and barley in our day-to-day cooking, though I do often forget to soak beans, and keep canned ones on hand. We put freeze-dried spinach in our lasagna, and use dehydrated celery in a lot of our soups. We also taste-test all of the packaged camping food we keep on hand - occasionally we'll cook one up instead of heading out to a restaurant when we're feeling lazy. If we ever really need to use any or all of this stuff, we will know that you need to add extra water to the camping packages, and leave them sit five minutes longer than is called for. We know what dense WW bread tastes like, and have developed a taste for it. We know how to soak and cook the beans so they are not crunchy. We have figured out how the dehydrated and freeze-dried and canned veggies will work in our regular recipes.
One major point about dietary change - if you suddenly switch from fast food and Kraft Dinner to a diet of whole wheat, rice, and beans, your guts will not be happy, and you can expect an adjustment period of gas, bloating, and running to the toilet. Again, not something you really want to be dealing with when a crisis hits. Personally, I'd rather get used to it slowly, and not have to change my eating habits much in an emergency.
Having said all that, we love our fresh fruit and veg around here, and we do buy out-of-season stuff from the store all the time. We are learning to root cellar and can, and to cook seasonal food. Even with the focus on seasonal cooking, I'd imagine we will continue to buy occasional out of season treats, while we can. However, if, for whatever reason, we could no longer get spinach and red peppers in January (we live in Canada), we'd be able to cope with what we keep on hand.
I would expect that a lot of the resistance to the idea of eating what you store would come from folks who eat a lot of packaged food or take-out...maybe no-one has ever showed them how to cook. Maybe they think is is really complicated, or takes tons of time. My advice to them is that cooking does not have to be difficult or fancy like the gourmets on TV - go get yourself a good, basic, comprehensive cookbook like the Joy of Cooking, or get your Mom or Aunt or Grandma to share some old-time recipes. Cook extra, and freeze the leftovers for lunches, or for meals on nights when you don't feel like cooking. I work full time and still cook most of our meals from scratch. Start trying this stuff out. It's cheap, and not all that complicated...