There is art which belongs in museum display cases.
This is not that kind of art.
Furniture is functional, and these pieces are intended to function.
Use is exposure history.
It may not be an event worthy of the annals of world history when you spill that bottle of wine at your party (although, of course, it might be).
Either way, the stain will record it for posterity. Furniture has a special way of remembering things.