Harvey, that quote is hilarious.
Laura, great question as always. The answer is group dynamics, separation and degrees of danger.
I was hiking with two others and I recomended that we bivy at one of two fairly sheltered places that were maybe 400-500 vertical feet below the summit but I got outvoted. Once we were up there, we separated into three separate windbreaks. Nobody else could hear me puking. As miserable as I was, it wasn't so bad that I felt the need to wake the others at 3 in the morning to go down to where I had hoped to sleep in the first place. There was also probably an element of diminished mental capacity--exhaustion and sickness don't make for great critical thinking skills.
And by the way, that picture and the shelter. Wow.
