What does krakauer think about the relationship between Franz and mccanless?

Franz saw McCandless as a son.

When Franz met McCandless, his long-dormant paternal impulses were kindled anew. He couldn’t get the young man out of his mind.

Chris saw Franz as a good friend, and I believed he care about him immensely, but Chris was also uncomfortable with Franz's desire for a son..... his wish to adopt him.

At one point Franz dared to make a special request of McCandless. “My mother was an only child,” he explains. “So was my father. And I was their only child. Now that my own boy’s dead, I’m the end of the line. When I’m gone, my family will be finished, gone forever. So I asked Alex if I could adopt him, if he would be my grandson.” McCandless, uncomfortable with the request, dodged the question: “We’ll talk about it when I get back from Alaska, Ron.”