This is true. And I'm sure there are a fair number of other cheap/healthy dishes people could suggest. But there's also the matter of time needed to prepare, and the fact that a family is rarely going to be disciplined enough to all want to eat such a meal most days.
Personally, something I'd like to see more would be a bigger push for more food that's actually healthy (or at least portioned correctly) from takeout/fast food joints. The regular staples don't necessarily have to go, but I think it's time to react to the fact that busier families often rely on eating out, and stop working under the assumption that a meal out is a "treat."
Really, when someone goes to a fast food place and orders the #1, I think there should be a bigger push to ensure that it's not garbage that's awful for you.