Don't have time to read the link now, but yes, we have food deserts. Detroit is one of the worst cases--probably mentioned in the post/article.
There's always private industry solutions: Ikea runs a private bus several times daily from Campus Martius (downtown Detroit) out to Canton, the wealthy southwestern suburb where the store is located. Of course, they mostly sell novelty foods, but they have a low-cost restaurant with more "real food" that is to be found at McDonald's et al.
If Wal-mart ran a private bus line from key locations in Detroit out to suburban stores, I bet they wouldn't lose money.
The problem in Detroit now is substantially one of population density. It's as thinly populated as an outer suburb, but very few people have the ability to travel far because of transportation issues. The cost of auto insurance in Detroit is sky-high, for some reason. Mostly, actually, not due to theft, although that is a major factor, but mostly because most drivers in Detroit are uninsured. Don't have a reliable source, just the word of friends who live there.
It is a real problem. Crime is high and neglect is higher, but there are a whole lot of good people trying to live their lives and it is increasingly hard to survive as Detroit becomes more and more of a burned out pit of despair. Friend of mine bought a house there for $8000, and has spend several times that in the legal hours working on ousting squatters. Sometimes, it's handy to be an unemployed laywer.
Sorry to be rambly, I'll read the link when I get a chance and can comment more intelligibly.