What the hell are you talking about? It's WAY cheaper to feed your family from the fresh-food section of your local grocery store than at a fast food joint...people are just too lazy to make the effort.
Do you have any idea how cheap it is to buy healthy essentials like bananas, apples, broccoli, rice, pasta, beans, etc.?
A "value meal" will cost you $6...I'd guess that my typical meal costs about $3 eating the types of foods I just mentioned.