I think two factors matter: lack of housing and shift to service sector. The lack of housing forces people to prioritize money, just Maslow's hierarchy. Because

I think two factors matter: lack of housing and shift to service sector. The lack of housing forces people to prioritize money, just Maslow's hierarchy. Because many jobs now involve sitting at a computer screen for 60 hours a week, not many (healthy/sane) people who want to add even more hours at the computer on top of their 60 hour a week 9to5, or 7to7, or whatever most people now work).