Why was Hemingway's "story" Pursuit as Happiness left unpublished?

Curious to find in the New Yorker summer “double-issue” a previously unpublished short story by Hemingway. Or is it a short story? In the online edition a brief q&a w/ Hemingway’s grandson Sean answers, and raises, several questions. Sean H, preparing for a new edition of Old Man and the Sea came across the manuscript among EHs papers in the Kennedy Library. The papers date from anytime from the 30s to the 50s. The story as published – Pursuit as Happiness – bears clear relationship to Old Man, but it feels more like a memoir than like any of EH’s other many, great stories: the people in the “story,” including the narrator, EH himself, are referred to be their real names, and there are a # of references to EH’s writing and his writing practices, quite unusual in his short fiction. The piece itself involves EH’s attempt to land a +500-lb marlin off the coast of Cuba, and it exudes all of the so-called manly virtues of the hunter – will win no fans among those opposed to the slaughter of animals for sport! – and gives a real sense of the physical difficult and needed dexterity in the landing of such a prize. Well, it gets away, to the great chagrin of the 2 crew members who should, but seldom do, deserve as much recognition as the rich guy paying the fare for the “sport.” It would be my guess that this was an early attempt to EH to write about his fascination with deep-sea trophy fishing; he must have set this aside until he figured out a better way to pretend the material as both a sporting story and an allegorical narrative, which he ultimately did on Old Man: same material, but without the author’s presence and with the fish getting away not because of a crew-member’s mistake in cutting the lines but, after the successful catch, the carcass gets devoured by sharks en route back to port. In the novel, unlike this unpublished fragment, the struggle itself is its own source of victory – even w/out validation and recognition from the world at large.