One problem in a place like Detroit is that most properties aren't even
assets anymore ... they're
liabilities. That's why there have been a number of properties in Detroit in recent years that have been listed at $1 -- with no takers. If the prospects of doing anything meaningful with the property are years away, then demolition costs and the cost of carrying the property (mainly insurance and taxes) are likely to exceed any investment returns you may get in the long run.
Interesting that the Chinese are interested in buying these properties, though. This is one way we are likely to recover much of the massive U.S. trade deficit with China.