I wonder if it's generational. McCandless was six years older than me. That means he was in 10th grade when Challenger happened, 8th grade at the Sarajevo Olympics, 7th Grade in the Lebanon barracks bombing and 22 when we bombed Iraq the first time. We were all right in that formative era when the world changed - in 9th grade debate class I argued against the reunification of Germany. It was the kind of crazy time where Fukuyama was arguing for "the end of history."
And I knew lots of guys like this. It was the original GenX "fuck this shit" approach that led to characterization in Slacker, Reality Bites, etc. McCandless is 100% a character out of Douglas Coupland's Generation X (which came out the year before he died). It wasn't that they were accomplished outdoorsmen. It was that they didn't care, couldn't be made to care, and were busy opting out of society 100% because they had no faith that it could be improved or engaged with in anything but a negative way. They weren't "off-the-gridders" so much as they were burnouts. Maybe it had something to do with how much more common acid was back then.
That, I believe, is the thing that Krakauer worships. It's the fatalistic attitude that if this life isn't worth living you're better off dying than trying to adapt. Krakauer wants McCandless to be a countercultural hero, not a poacher burnout that doesn't believe in maps. If his struggle is noble his life isn't in vain; if his struggle is ignoble then The Man was right all along and The Man must never be right.
Richard Proenneke's book had been out 19 years by the time McCandless headed out. It was a thing. Dick Proenneke basically proved it could be done - and that with aplomb - if you knew what you were doing.
But if you know what you're doing, you're not pure of heart or some shit.