I mean, it's partly its fault, sure. To see what happens if you completely let corporations dictate your diet, look no further than Super Size Me.
But also, that's kinda abdicating responsibility a bit, don't you think? My in-laws live in North America, but cook traditional homemade chinese food (and they were teachers by trade in China, so the "low income peeps don't have time" argument doesn't exactly fly either).
It costs them something to the tune of $150 a month in groceries to feed 6 lavishly when we go visit (probably even less otherwise because they're even thriftier when cooking for themselves). The fact that the vast majority of americans don't know how to cook rice in a regular pot, or pickle their own radishes is largely due to its culinary culture (or rather, a lack of it).
In Japan, there's the concept of Yamato Nadeshiko, a desirable set of traits in a romantic partner which involves among other things being excellent at home cooking. I'm not aware of this kind of intertwining between cooking and other aspects of life in the US. IME, cooking is mostly just seen as an annoying chore, or associated with snobbishness.
Another example: there's animes/mangas portraying cooking in home economics class in school (like cutting veggies and making rice). The closest I've seen in the US so far is third graders making homemade ice cream (which is basically just dumping cream in a bag of ice).
Point being, I think there's more than just corporate narratives when it comes to culture.