Huh? In the US, median rural income was $40,135, compared to $51,522 in metropolitan counties. [1]
Things that are for sale, are generally for sale in cities. Want to buy something? Your best bet is a city.
Please tell me how long the drive from SF to the nearest Walmart is.
Cities aggregate enough people that you won't be the only person like you.
This is a very good point. Lots of interest-based communities form in cities. In suburbs, there would not be a sufficient "critical mass" for this kind of community to exist. It drives business too - there are, for example, restaurants in cities serving niche foods. They would never have a large enough customer based outside of a highly-concentrated urban area.