Well, they don't live there, but they spend probably 10 hours/day there, or 60% of their waking hours. Where someone sleeps doesn't seem too important.
I would say what a person does with their life outside of their working hours is rather important actually, particularly when we're talking about the life and culture of a city.
Zurich and Oslo, I don't see the connection, they both have workers of all kinds, old and young people. They're organic and alive cities.