One more point I don't think that I mentioned: Mac-n-cheese in America
is, for many low-income families, a staple, just as other items like
beans or rice are in other countries. Macaroni itself is cheap, as is
the boxed version of macaroni and cheese. Mothers in a hurry often
serve it to their families as a penny-pincher meal to stretch their
dollars...and it also is popular among Catholic families during the
Lenten season on Fridays (or it was when I was growing up). As I think
I previously mentioned, it is popular as a side dish with fish, too.

My husband and I have generally always had to live on limited income
for one reason or another, and macaroni and cheese (yes, the boxed
variety) often served as dinner when we couldn't afford much else. Or,
when we could afford meat, it often served as a side dish. I usually
dressed it up with whatever I had on hand -- olives, salami, a little
ham, or various spices; maybe some leftover sour cream, perhaps some
onion. It worked for us!

~Eri in TX