It's both isolated and largely residential. Not a lot of large stores, just a lot of University of Chicago buildings. It's the most isolated place in Chicago where white people are willing to live. Source: 40 years old, born in Chicago, live in Chicago, attended Ray School and Kenwood, sister taught at UofC, never had a driver's license.

Also, Chicago is a designed garden city, enforced by zoning. It's largely and intentionally built up of huge residential arrays of city blocks, a half mile to a side, separated by boulevards where all businesses are packed. So, if you live in the middle of one of these blocks, it's 10-15 minutes of walking to see any business. If taking away drivable areas were accompanied by changes that allowed businesses to be built within those areas, like corner stores, I guarantee that groceries wouldn't be a half-hour away.

edit: that's what I get for reading comments before the article. Chicago is perfect for superblocks. It pretty much has them already.