Why did krakauer interrupt the mccandless story with chapters 8-9?

In this section, Krakauer describes the other famous and infamous characters to whom McCandless is now often compared. At this point, Krakauer feels it's necessary to make his own beliefs clear—that though McCandless shares some characteristics and behaviors with these men, the only one who is truly like him is Everett Ruess. Carl McCunn was more naïve, John Waterman was actually mentally insane, but Everett Ruess was, like McCandless, simply deeply in love with the land, very romantic, and passionate about living by his principles. These comparisons show that removing oneself from society and living riskily can be a symptom of insanity or stupidity, but it is not inherently so.