Well to view this through a political prism, Hemingway, DH Lawrence, Sylvia Plath, were babies born out of the industrial revolution and the first generation of addled navel gazers starting with Wilson that gave us modern socialism. It’s been downhill since then. My 9th grade daughter’s history book still has the Rosenbergs a s innocent victims when we know now they were communists and Soviet spies, so hero worship of Heminway is in their playbook. I personally liked Hemingway as an author, but as a human being he was a horrid Father, serial fornicator and a bad drunk. So being a non principled traitor is not too far a stretch.
Hemmingway was a principled traitor; and the principle was international communism.
People usually turn spy for one of a few reasons...
Ideology.
Money.
Sex.
Ego.
Didn’t he fight for the communists in Spain?