I believe it's still the most segregated area of the entire nation, including the deep south. Which fuels a bit of that entitlement mindset, because it's ground zero for a continual parade of people coming into to rant, speak of, and spew rhetoric about entitlements. Sort of a vicious circle, in a lot of ways.
Well, white flight to the 'burbs began back in the Fifties and without a lot of change, blacks pretty much stayed in the city. As the bombed out, burned out, drugged out, and trashed out area of Highland Park can testify. I remember my grandmother living in HP in the early Sixties and back then, it was a nicer neighborhood. Not any more.
When I was a kid, I can remember people talking about Garden City (where I grew up) being devoid of blacks, while Inkster, one-half mile to the south, was probably 50% or more black. GC has since "opened its doors" so to speak, but not by much.
In short, you're right. Detroit is heavily, heavily segregated. Hell, even the muslims pretty much hang out in Dearborn and certain areas downriver.