The biggest problem Detroit has is declining population of income-producing people. Yes, there are issues of businesses for people to work at being in the city, but let's face it, people will drive to work wherever they are, at least until there's much better public transport there.
Businesses get tax breaks to locate in particular areas - why don't residents? Michigan could/should introduce a 10 year state tax holiday for residents of Detroit. If you live in Detroit the city, you pay 0% state income tax (or... a reduced sliding scale or something like that).
People will move there. People will relocate there. Supporting businesses will follow - more restaurants to serve local residents - residents who are earning, not the left-behind/leftover residents of a hollowed out city. Almost everyone who can get out of Detroit has already.
Efforts of entrepreneurs to turn things around are good and should be applauded, but the problem is of a bigger scale than most people realize, and imo should be tackled at a state level via tax incentives (a great social engineering tool). One rebuttal I got to this is many in surrounding areas (Royal Oak, Ferndale, Easpointe, etc) would object because they'd be losing residents to Detroit. It probably would happen some, but the entire area has lost a lot of population as more people leave the region (and state) than move in.
As companies try to lure people back - I've heard from more than a few people that Ford is hiring aggressively - "no state income tax if you live in Detroit" would be a nice extra incentive.
[1] http://michaelkimsal.com/blog/solution-to-detroits-current-p...