"It has everything to do with the rise of cheap, processed garbage in the 50s. You never saw people in the past morbidly obese unless they were rich. Why? Because rich food was expensive food. But now I don't have to spend 3-4 hours every single day making proper food for my family, and can just open a can? Or better, just drive-thru McDonald's? Yay!!"
I agree that this is a significant factor, most people don't have the time to cook anymore because they have to work so many hours to make enough money. Most people are unlikely to have the energy to spend hours cooking after they've spent a day at work.
"But here's another dirty little secret: pound for pound, fast food is MORE expensive than good, quality, organic food. It just takes time to make it."
Not only is healthy food often more work and unless you know what you're doing, less filling. It requires either knowledge or the confidence to learn what to do.
If you want to help people, shaming them is not an effective way to go about it.