We've all read Moorcock, or Lieber, or Tolkien, or Vance, or Abercrombie, or Eddings, or almost lost it when reading Donaldson. That's the Fantasy we are talking about. Until I smoke what Guvnor has. Then then it is that one. With pursuing rave squirrels.
I was making the point that D&D or even RQ style fantasy can be very prosaic, and not very fantastical.
"M. John Harrison acknowledges Tolkien’s position as the first and last word in fantastic fiction, but begs readers to look more closely, where they will see not the “beautiful chaos of reality,” but “stability and comfort and safe catharsis.”" http://www.newyorker.com/books/page-turner/anti-tolkien
So, the value of this D&D-medievalist-Tolkien fantasy roleplaying as a game is comfortable and safe catharsis within recognisable and non challenging tropes. Yup, that's my answer.