That certainly makes sense, and I agree, but I interpreted the parent comment ("our urban conditions are primarily reflective of the vastly unequal socio-economic structure we have at large" and "In places where the working poor are the most disadvantaged, there also tends to be the highest auto dependency") as inequality being a cause of our poor transportation infrastructure, instead of our poor transportation infrastructure making inequality worse.
I agree that I perhaps poorly framed my comment earlier. By reflective, I think I was really thinking of a cyclical relationship. Where lack of transportation compounds inequality, I also believe that inequality is at the very least, co cyclical with poor infrastructure due to a lower interest in collective investment in that infrastructure and greater private control in development.
An example of such would be Atlanta, where public transit investments have been sparse due to wealthier areas of the metro having little interest in funding transit. Many wealthier residents live suburban developments that are highly car dependent. As the article points with walking, many wealthier areas opt to avoid transit access, many residential areas do without sidewalks and follow a land use pattern that (effectively) cuts the neighborhood off from pedestrian access
