It didn't work with the Royals
There aren't any known investors
No fan interest
Economy/Not enough people
Yes! Cincy should get an NBA franchise
24 Years and Counting...
While Louisville does deserve some form of professional sport, basketball doesn't seem like the on to be going after. Cincinnati and Louisville just aren't basketball cities. Baseball, actually, seems like their best bet to me; the absurdly high attendance rate for the Dragons and Bats proves that being that close to Cincinnati doesn't result in a lack of interest, and it already has a reputation as a family-friendly baseball city with the Louisville Slugger museum. Small TV market, but they have the entire state to promote to. Plus, it would be an awesome rivalry with our Reds!
Look at Baltimore with the Orioles. When the Nationals moved in, Peter Angelos was up in arms because he considered Baltimore/Washington a single media market. It caused such a stir that the Orioles now hold the broadcasting rights to the Nationals games as part of the agreement to move to Washington.
The only reason basketball could possibly work is because both Louisville and Kentucky are college basketball crazy and Louisville/Lexington have the media markets to make it work. The question is whether or not the people in Kentucky would support a NBA franchise. Most UK fans could care less about the NBA, they only follow to see how the former Cats are doing.
The NBA may have to contact 2-6 teams, so that's one reason why Cincinnati doesn't have an NBA team. Like others have mentioned Cincinnati is way way way down the list of possible places the NBA might land if a franchise was to move.