I think that this has been included in the text because it shows that Joe and Simon are very ambitious people and are willing to do whatever it takes to achieve their goal. This also reveals that Joe and Simon are very dedicated to climbing that they are almost being controlled by the mountain that they are trying to climb. It also shows Joe doubting why he was attempting to scale Siula Grande, was he doing it for pleasure or was he doing it for glory and egotism. It shows that the dangerous men mentioned are doubting why they are doing what they are doing.
Raise your voice, open your mind, unlock your imagination