This city-bashing material is very tired.
Chicago was, and still is to a certain extent, home to a very large, mostly lower-to-middle class immigrant population. Numerous urban development models have shown that this set of circumstances is what creates a very dense, vibrant central city area. A large population of people with no access to private transportation created an environment where all neccessities for living were located within a small area.
Detroit, on the other hand, is the birthplace of the American automobile industry. The Big 3 automakers have wielded tremendous power over the development of Detroit, and paid very honest wages to their employees even during the era when factory workers were underpaid and overworked. These employees were able to purchase a car of their own, and as a result move to an area that they saw as more serene, further away from the central city which, even in the most prestigious downtowns like Chicago, Manhattan, and Boston, was viewed as a center of filth and poverty. The Detroit metropolitan area boasts some of the most prestigious suburbs in the entire United States. As JackTalkThai indicated, Oakland County contains both the 2nd and 4th richest (per capita) zip codes in the country. Unfortunately, as money left the central city, downtown has suffered.
Recent efforts to restore the Detroit's CBD to its former glory have produced some nice projects, but make no mistake about it, there is a ton of work still left to do. It may not be pretty, but its certainly not dangerous. Take a trip out to Royal Oak or Birmingham next time you're in town for a game and you'll find entertainment districts on the level you may be accostomed to.
As Chicagoans you are blessed with probably the most American of all downtowns, somewhat ironic considering that it was mainly the result of the socio-economic status of 1st generation immigrants. You are also cursed with wicked congestion on your freeway system, and all of the other effects that come along with density.
Point is, I guess there is no point. Just thought I'd try and explain to some of you who may be interested why cities look like they do.