If you think it's hard to live on $50K salary in San Francisco you should think about how everyone else in the service industry supporting all those tech workers manage to live on minimum wage or barely above that. Think about the people serving lunch, or making coffee, or cleaning offices, etc. Where do they live and how can they afford to be in the city every day at less than half of $50K per year? Working remotely isn't an option for them either.

If it's truly prohibitive for a single person to live in SF for $50K per year then we should be really concerned about the families that earn $50K from two minimum wage jobs, and need to support 1 to 2 children on top of it.