Ability to walk quickly at altitude is in fact a skill one can improve with repetition. Your lungs become acclimated to the practice and it does become easier for you. It's fine to hike with others in the same condition, but to decide that others not in this condition are lazy is a pretty baseless assumption.
I believe this is actually a good metaphor for the other social systems the author mentioned. If you think poor people are just lazy or don't want to work you need to think about the way practicing having means makes your existence much easier IMO. Again, you can decide to leave others behind, but I know my life is better for both helping others and receiving help when I need it.