Culture definitely sounds like a component, I wouldn't be surprised to hear a crass criticism of your rice-and-beans meal as something eaten by "those starving children on TV."
There's also the issue that a lot of folks simply don't know how to cook. The benefit of a lot of those box meals is the hand-holding, instructions included nature. I buy a box, it tells me what I need to buy, and how and how long to cook each component.
I'm a bit embarrassed to admit, but if you handed me a sack of rice and beans I'd have no idea how and for how long to cook it. I simply never learned those skills. In the past several months I've realized how poor my culinary skills are, and have been working to address that deficiency, but for many folks in the US we simply pick the path of least cost and effort.
I think this is the "Part 3" to the list above. Rices/beans/potatoes can yield many, many different dishes. I can afford more expensive choices, but most of my meals still consist of these basic, cheap foods.
You can do a big batch of this and then later get fancy by throwing it around a frying pan, maybe add eggs and spices, and still be below $1 / meal.
Sure, but how long? How much salt? How much water? How big of a pot? Do I put them both in together? Separate? What kinds of spices? How much of each?
Ultimately, I can just toss 'em in and wing it or go Google it real quick but most folks just don't even get past the part of realizing "Oh hey, I don't have to do the same thing I've done for years." Most folks don't question their day-to-day rudimentary tasks, especially when they don't have to.
Having "broken" from the rut, it's rather amazing how complacent we can get.
Like hearing myself arguing with my SO.
- "Can you cook some pasta before I come home?"
- "Sure honey, but which one? How long? How much salt? How much water? Which pot?..."
Ok, I figured that one out eventually (definitely with the help of some instructions on a box, but they're often not reliable; first pasta I made I boiled longer than the manual said, and it still came out al dente). But the point is, cooking has ridiculous amounts of complexity hidden in it, including quite a lot that can be only be understood through trial and error.
I'd argue this is the most common case of technical communication problem between humans. My SO asking me to "just" cook a "simple" dish would be like me telling her to "just" make a "simple" JS gallery page. In both cases, we'll eventually figure this out, but it will involve lots of googling and stress.
As I think about it more, it really reminds me first getting into functional programming. These simple, primitive concepts appeared so daunting at first but once you get accustomed to the mentality and lose that initial fear you can turn those primitives into complex, beautiful software.
When I moved to the US, I was appealed by the price of vegetables. Carrots, beets, cabbage are all so expensive compared to Western/Eastern europe.
Carrots and cabbages are about the cheapest vegetables in the store. It doesn't even make a scratch in the bankroll.
Bell peppers, now that's another story.
Here's a study of how (among other things) longer-acculturated immigrants to the US shift their eating toward convenience foods:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3090681/
Study results corroborate previous research highlighting the negative impact of acculturation on diet of Latinos. Many mothers described ready access to fresh fruits and vegetables in their native countries, although availability of such foods decreased in the U.S.. Mothers further described how their lives had become increasingly busy and complex, leaving little time for preparing foods, thereby making the allure of convenience foods, often which are unhealthy, more appealing.
This study details the experiences of Latino families. A quick literature skim and anecdata from my own life indicate that it happens with other immigrant groups coming to the US.
Some low-income subgroups of the American population continue to prepare food from scratch. When I was growing up, some of my friends came from low-income fundamentalist Christian families. Fast/convenience foods were a rare treat; the typical meal plan was "find what ingredients are on sale or have good coupons this week, cook meals from them." (Also, stockpile ingredients that keep well at the lowest-cost times of the year. Buy 6 bargain turkeys around Thanksgiving.) This seems to hold regardless of specific belief; I've heard similar stories from friends who grew up in strict Mormon or Orthodox Jewish households.
Later in graduate school I noticed that students also did more of their own cooking than you might expect from their age and income level (ranging from "nonexistent" to "just above poverty line.") I certainly cooked. It would have torpedoed my budget to eat boxed dinners or fast food every day.
Maybe deep religious belief and extended education are also, in different ways, factors that make you less acculturated into the American mainstream. The irreligious recent immigrant from Belarus, the pious Catholic, and the chemistry postdoc may all be less likely to follow the American default dietary practices because they're living further from American defaults to begin with.
Another factor I've noticed is that these low-income households that cook their own meals (and otherwise make long term cost-effective decisions) tend to be low-income but stable-income. If you're on a graduate school stipend or have taken out loans, you don't have a lot of buying power but you're not juggling two jobs or wondering how many hours you'll be scheduled for this week. Likewise, in those low-income religious families where I saw meals planned around costs, they didn't have much buying power per household member but income was steady month-to-month. If you don't have a modicum of stability you can't be sure that "invest in a chest freezer, buy meat in bulk during the best sales" is actually a good financial optimization plan.
Outside of the USA you have plenty of families surviving on less than $10 a day, they don't wait for their paycheck to accumulate to buy food.
It sounds more like a cultural issue, or perhaps such staples are not easily found in most of the USA and/or are marketed as "health foods" and suffer a corresponding price increase?