This article is really more about the need to experience nature, and wild environments (non-urban), than it is about the "benefits" of solitude. In fact, it does more to point out the negatives of solitude (potential death from frostbite) than it does to highlight positives. Based on my own experience some solitude is healthy and positive, even necessary for deep work. But too much is quite dangerous for one's mental…
But of course the wilderness doesn't strictly mean not socializing. Talk to anyone who's thru-hiked the Appalachian Trail or similar and you'll hear about how social of an experience it was, between the times of solitude. The thing is that there is no solitude in heavily populated environments, where things like work are what you're supposed to do. This is the point of the article: in cities, in society, you're not able to focus on the simple joy of your existence, as Byrd was. In solitude you're free from the urban burdens and obligations that stress us, despite how well we've adapted to them.