Point out to me where there are family-sized dwellings in a safe neighborhood with a commute less than 30 minutes to the CBD affordable on the median household income, or even twice it, in London, or New York, or San Francisco, or Los Angeles.
Obviously one can move away, or to a dangerous neighborhood, or accept a brutal commute. But when one is from such a city, or can only find work in their chosen industry there, the distress is understandable. Many big cities have housing policy sufficiently bad that there are no good choices for the middle class, or even those significantly above it.