I don’t see the universality of a lot of “literature.” I’m not likely to pick up Dickens or Melville if there is a Clancy to read... even if I’ve read it before.
On the other hand, Sherlock Holmes is great stuff. Is that considered literature?
It's a safe bet that Dickens' Christmas Carol will be read and performed long after Clancy has been forgotten. And references to Melville's Moby Dick still pop up in popular culture from time to time.