hack value

hack value n.  Often adduced as the reason or motivation for
   expending effort toward a seemingly useless goal, the point being
   that the accomplished goal is a hack.  For example, MacLISP had
   features for reading and printing Roman numerals, which were
   installed purely for hack value.  See {display hack} for one
   method of computing hack value, but this cannot really be
   explained, only experienced.  As Louis Armstrong once said when
   asked to explain jazz: "Man, if you gotta ask you'll never know."
   (Feminists please note Fats Waller's explanation of rhythm: "Lady,
   if you got to ask you ain't got it.")