alt Hacker NewsDairy is completely unnecessary, for one. Its prominence on the plate makes everything else immediately suspect. There are probably some axes along which a glass of milk or cup of (unsweetened) yogurt is one reasonable option but that's not what is being promoted here.
I see it as more of a limit than a requirement. After all, you can technically satisfy your dietary needs with vegetables and eliminate fruits. But we aren't talking about technicalities and edge cases, rather what a balanced diet might consist of. For many people that does include dairy and fruits, even if neither are completely necessary.