Most of the problems are because the people learned a deviant social and economic system.
I'm from the suburbs and I love it in Metro Detroit. Real estate is cheap, so you can own a nice vacation spot up north on the lake for like 50-60k, lots of entertainment options, casinos, you can always find something to do. The decline of urban centers like Flint and Detroit was predictable, but it was managed poorly. To be fair, the death of a city's economy is darn near impossible to manage. But if you avoid the bad spots, there is a ton of good. Great restaurants downtown, four sports teams, the DSO is great, tons of concert venues, and you don't have to drive through the broke down neighborhoods.
As for the neighborhoods, of course they would be what they are. There's pretty much no economic opportunity or development in the city, other than downtown and a few small pockets where factories exist. If I was born at Woodward and McNichols, I would probably be selling drugs, guns, or something illegal to get by. The notion that people are going to choose the valiant option of starving over committing crime when they have very little opportunity is odd to me, and when people grow up surrounded by crime, well, people learn from watching the world around them and observing the good and bad from the decisions that other people make. If they see one person starving with no job and another person living decent by selling drugs, they're gonna sell drugs.
As for why doesn't it change in ways where criminal behavior is considered a bad option, well it seems to me that there are a lack of role models that illustrate that people can do well by living a straight life. Lots of churches, but the churches don't do much more than occasionally condemn stealing from big businesses or selling drugs to people in the community. Personally, I think church leaders should make plans to show how good works that improve the community also create opportunity. For example, there are a lot of beaten down, busted out homes in the city, a lot of brokedown cars that get tagged, towed, and demolished. Teaching how to fix things like homes or cars and do things with their hands would mean they learn some skill and see how the skill results in creating something positive in real-time. In doing so, they can also take something they obtained for free and obtain title over it while fixing it. I believe that the American Black is lazy because he learns to be lazy, not because of genetics. If they see the personal benefit of improving their community, they will be more inclined to do it. Detroit is like it is because when the jobs left, so did the adults to teach the children to do something. Community leaders and institutions need to step-up to that challenge.
There's a lot more to it, but this is too long as is, so I think I will just

here.