It saves labor if staff does not have to set up tables for every meal. In cold or rainy weather, a school gymnasium is needed as a lunch hour recreational and physical fitness facility. Think about a dinner party with half dozen or so close friends eating in a fine dining room. Compare it with a typical school or even many family mealtime routines. Good architecture provides spaces where strangers interact to become friends.
Today there is a serious integrity problem with much of our constructed and manufactured design.
We live in plasticland of contradictory and untruthful visual relationships. Children growing up in an environment of pretense are being conditioned to excuse and rationalize fakery as quality on the basis of a quality surface appearance while its heart is actually plastic or sawdust. Plastic can be given design that does not need to look like another material to be beautiful. Good designers can make beautiful texture, color, shape and form from plastic without faking another material to do so. Children need art lessons to critique their environments in terms of truth and lies.