What I have enjoyed about the majority of the narratives we have read this semester, with the exception of perhaps The Eiger Sanction and Into Thin Air, is that the adventurers in them have been climbing/exploring for simply the sake of doing it and for the glory that went along with it. Thinking about it, not one of these adventurers had any political or economic benefits from their adventure. Their only rewards were personal satisfaction, and in some cases national honor and glory. And I respect that. I feel that really sets them apart from the Rob Hall's of the adventuring world (though I mean no disrespect to him). They adventure for adventure's sake (the title of my post :) ).
I think this really becomes apparent in Endurance. Shackleton for one, really has no viable reason for undertaking the expedition. Although being the first successful trans-continental expedition across Antarctica would bring Shackleton national honor, the real reward would be in simply doing it, rather than any monetary windfall. He also really didn't care much for the supposed scientific benefits of the journey, only taking on scientists to secure some funding. No, Shackleton wanted to go on this expedition because he wanted to go on a grand adventure, and nothing was going to stop him from doing so. And in my opinion, it makes this a true adventure narrative.