Why did Krakauer interrupt the McCandless story with Chapters 8-9?

In this section, Krakauer describes other famous and infamous characters to whom McCandless often compared. In these chapters, Krakauer finds it necessary to clearly state his own beliefs—that even though McCandless shares certain characteristics and behaviors with these other men, the only one who is truly like him is Everett Ruess. Carl McCunn was naïve, John Waterman was mentally insane, but Everett Ruess was, like McCandless, simply in love with the land..... a romantic, who was passionate about living by his principles. In these comparisons, Krakauer illustrates that removing oneself from society and living riskily can be a symptom of insanity or stupidity, but it is not inherently so.