So this seems particularly dumb if thats the inspiration
If you have an economic perspective for the hero, yes, most of the time heroic is dumb (standing up for what's right to your own economic detriment, fighting a patent troll in court, risking your life for a stranger, etc). But being heroic is not about economics. It's almost precisely the point.
Generally speaking, heroic is not dumb, but almost always requires a lot of risk. We consider people heros or heroines because they take on risk to do the right thing, which is often the thing the masses are unwilling to attempt and/or unable to accomplish.
It certainly helps to accomplish, but most people will consider heroic acts those that take on a lot of risk to do the right thing despite the outcome.
For the book's author, Jon Krakauer, the story is a personal one because he himself did stuff just as dangerous when he was younger. He tells a story of solo ice climbing when he almost died. I think Krakauer is fascinated by McCandless because he could have ended up the same way, and he's grateful that he didn't. Krakauer lived and adjusted to being an adult in our society. He grew up. That's what I find tragic about McCandless and the people idolizing him, and dying trying to follow his footsteps. I think that if McCandless had lived, he would have eventually adjusted to society as well.
The lesson: its a good idea, but don’t run in unprepared, and don’t think nature is without danger
The apparent takenaway: it’s a good idea
But regardless the movie depicts it as a fairly slow, very painful, and a fairly pathetic death (alone, weak, with lots of regret and little to show for it), but still 90% of the movie was him running around in gorgeous nature shots and small towns.