There is a large market of people. Unfortunately all of the issues I listed are stopping them from moving in. Detroit should be full of middle class families, just like Chicago, New York, Boston ....

Until the city of Detroit can draw back middle class families it is not going anywhere.

Also you seem to envision Detroit as a Extreme high density city. Most of Detroit looked more like Royal Oak than Manhattan. Most of the inner ring suburb have the similar densities as Detroit had at it's peak. Detroit never had the Density of the east coast cities and never will have.