If you want to become rich, you don't sell custom yachts to the upper class - you sell a $1 toothbrush to everyone in China.
In fact, selling yachts is a pretty good living. I don't see a lot of ghetto yacht stores 'ya know. Seems like they live in places like Marina Del Rey, and that's not too shabby.
Coffee consumption might be seen as decentralized, but not the production. Same with wine. Sure, people drink wine all over the United States - for example - but most of the production is done in California, and at that, most of it in two counties, Napa and Sonoma. They may well be putting garlic on the Cheesesteak in Philly, or using it for other things elsewhere, but its coming from around Gillroy California. 99% of the garlic in the US comes from that area. The auto industry has a few plants hither, dither and yon, but the fast bulk of auto manufacturing (and to the degree possible, the parts also) from a bunch of concentric rings that expand out from Detroit. So Michigan, Ohio, Indiana (By the way, not by change either, these states were the leaders in auto production when it was being invented, so its nothing new) are more affected then say, Utah, when auto production goes on the skids. Or, when its on the upturn. Sunnyvale is just 137K people, but the amount of computer stuff that goes out of that town has any other town (that's not it's neighbor like Cupertino or Palo Alto) beat in that industry.
From the beginning industry has clustered, seeking not decentralization -- look to Feudalism for the best example of how that is done -- but to concentrate supplies/raw materials/labor, production management/administration, and distribution.
The cities and metroplexs are a direct result of the industrial need for labor. Prior to industrialism (Say 1776 or so) cities were not even close to the populations that would come later, and that population was much more evenly distributed across the entire landscape. So the effect of industrialism was to centralize both population and industry. Stuff that required wood was located near forests, places that needed coal would build up around the coal areas, and people selling yachts live in Marina Del Rey and not Wichita
