I think they're asking what makes CL noteworthy among all the other PLs such that it keeps getting brought up, even though it's not new and shiny or widely popu

I think they're asking what makes CL noteworthy among all the other PLs such that it keeps getting brought up, even though it's not new and shiny or widely popular these days. Same sort of question you'd get about Smalltalk or Haskell.