Eh I bought my place 8 years ago, and I wasn't rich when I did it. I lived in a not-crazy expensive apartment on the edge of the Tenderloin (good side of California but close enough to keep the rent cheap). I was in that apartment for 8 years before buying a place. I got paid OK, but not baller. I worked for some startups that paid very low and sometimes missed paychecks.

I guess my point is that yeah, it can be done (buying a place in San Francisco and doing well). The problem is that newcomers (and especially younger people) see a job offer from FlashyCo (Uber, Twitter, Salesforce, etc) as a meal ticket good for living the ultra good life (fancy car, fancy new apartment, etc). When they look at what it costs, they get upset and dejected. Many people today feel that they should be well on the path to Easy Street by their mid to late 20's. Traditionally that hasn't been the case at all. Wage earning really doesn't pick up until your late 30's to early 40's. But tech screws with all of that. Huge acquisitions, instant wealth, engineers over 40 age discrimination, etc. So in some sense people do feel helpless when they're living with 8 people at age 30 (protip folks: get a 1-2BR in a less hip area).

A man was expected to provide a home for a family in his 20's, up to one generation ago.

It was also expected to be done on a single income, while the wife could stay home to take care of the children.

I would say at least 2 generations ago. Those expectations died in the 1970s.

It depends highly on the region and culture. In some areas of the U.S. these expectations are still around (and quite achievable).

Yeah I wouldn't say a man in his 20's was expected to "provide" for a young family in urban areas. Maybe in the burbs with a rented home or a smaller apartment, but not white picket fence typical Americana. Then again, 10 and 15 year mortgages were the norm back then...

If you're rich practically anywhere can be great to live.

The point, though, is that if you aren't rich, SF is a pretty bad place to be, and there are a lot of other places where those on a middle/lower-middle income can have a great quality of life.