New York and Newark are nothing like Detroit right now. Both are going through a great revival. There are a lot of reasons why, but it really has nothing to do with machine politics, ivy league educated people, or anything else you mentioned.
In my opinion, most of the credit goes to better policing, everything else follows the drop in crime.
I very nearly agree with you, but I'd argue that policing has little to do with it as well.
Detroit's crime rate has plummeted since the 1970s along with the rest of the US, despite no widely-celebrated crackdown. [1] Indeed crime rates have continued their drop from even the early 2000s despite a police department that was rapidly shrinking and increasingly mired in corruption/abuse investigations over that same time frame.
What's holding Detroit back, imo, are uncompetitive services caused by too few funds to cover too much sprawl. Even as the downtown enjoys a modest revival, the neighborhoods are non-options for anyone who wants to own a home. Particularly when functional suburbs with lower taxes and great schools are less than thirty minutes down the highway.
The city needs consolidation.
[1] The only anti-crime campaign I can even recall, was the mid-90s community effort to combat Devil's Night.
Very interesting perspective, I'll admit I know little about Detroit although I have been there twice in the last 2 years for a few days on business so I have seen the city in its current state.
In my opinion, most of the credit goes to better policing, everything else follows the drop in crime.