Someone put a very good comment on the Times website about this - people work to damage their health and then they spend the money they earned on fixing their health.
I think that's a short-sighted view on it, and I say that as someone who never had the slightest interest in doing it and would run like the wind if GS for some reason approached me. People have all sorts of reasons for doing it, some better than others: money, prestige, intellectual stimulation, getting a career kickstart (no one suffers from having worked at GS), working with a high performing team, thrills, liking a fast pace, supporting other people and/or having a strong drive to escape poverty and establish security.
In any case, most people either discover fairly early on it's not for them long-term and recuperate fine, or find a way to make it manageable for themselves. My ex GS friend is now a hedgie still making the bucks but working perfectly livable hours.