For a corporation that is flush with cash, Detroit is potentially a good buy with long term potential. A 50 year timeline is not unrealistic.
Such as, say, Dan Gilbert and Rocket Mortgage.
Is it a better buy than somewhere else is the big question though. Sure maybe you'd make your money back in 30 years but that's not what gets investors going. Otherwise everything would be powered with nuclear energy by now.
Detroit going bust is bad if all of your property is in Detroit, but if you have property in 100s or 1000s of cities then the individual booms and busts become less relevant.