-1. Real estate is CHEAP there.
-2. Proximity to major resources and infrastructure remain.
-3. Opportunities abound for the motivated & financed.
To wit: an area of reconstruction could be carved out and defended, given enough willing to make it happen & defend the effort.
If you invest in RE in Detroit, you make yourself a target of the taxing authorities.
No thanks - plenty of empty land elsewhere.
And OBTW, much of the infrastructure is gone - either decayed or stolen.