What I took from McCandless story is his very confused relationship with his father, and that was the driver in pushing him to attempt the "heroic gesture", and perhaps drove him to remain when it would have been obvious to most other people that he was in extreme danger early on.
I wasn't up for watching the ending of the movie, of him perishing. There wasn't anything left to learn about a very muddled young man, and little would be served to simply watch him die.
