Re: "You can get 2,000 calories for a couple bucks." Extraordinary claims require extraordinary evidence. Can you please let us know how can you get 2,000 calories for $2?
Rice bought in bulk can certainly be had for that price per calorie with some left over for a little protein. I don't recommend anyone follow such a diet though.
I'm a little surprised you didn't get scurvy, or have bone health issues (because of a lack of calcium or vitamin K2), have electrolyte imbalances, or have imbalances in fiber and essential fatty acids. But good for you. Thank goodness we don't base nutritional advice on anecdotal evidence.
Everything after that is preference substitution.
This doesn't invalidate consumer demand. People judge society and ultimately governments based on if they are able to obtain their preferences.