The writer and the reader seek escape in suspense, character and plot

Joanna Kavenna wrote a long article about John Banville in the  New Yorker a few weeks ago.  Banville is a serious novelist, winner of the Booker Prize for The Sea, who also writes mysteries. He is quoted as saying that one day he sat down and wrote 1500 words of a mystery in place of his usual 200 words for his literary novels.  And he has continued to write mysteries. Kavenna describes his literary novels as prose poetry, without too much concern for character and plot. I bogged down in Banville's latest such novel, The Untouchable, and turned to his latest mystery, A Death in Summer. He wrote it under the name Benjamin Black.

So, readers, what does it mean if both writer and reader feel the need to escape serious literature?