My reading of the article is that the author is spending a lot of words on saying "Look, this is why being selfish asshole is actually good! And if you don't let me be selfish, you're actually the asshole! You should award empathy to privileged people first, they deserve it more!" which is terrible message, even if the article was well written, which it isn't.
It was already disgusting message about hiking, the moment the author said "you can also apply this to poverty and obesity" he crossed the moral event horizon.
Both on hike and in society you have duty and responsibility for others - and that includes slowing down for them when necessary, both physically and metaphorically.