Jack London never really lived out the rugged and romantic lives of his stories/characters! Alex's admiration of Mr. London is actually for his imaginings rather than his lived reality.
What really begins to become apparent when reading the story is that Alex is an idealist, rather than a realist and this is what leads him to his death. He has so absorbed all of the setting and grandeur of the Jack London novel (even naming his own dog, Buck) that he does not stop to realize that Jack London was an author! not an explorer or survivalist.