For lower income people to afford.
When you live paycheck to paycheck you are often shopping for ~2 weeks of food at a time. Fresh fruits and veggies do not last that long in most places.
Healthy other foods also have less preservatives. Not to mention the time cost of preparing them.
I know there are multiple 'experts' out there that swear heathy eating is not more expensive... But that has never been my experience. Eating healthy is a luxury.