[errantmind]

This depends on other conditions being good as well, like being bike/pedestrian friendly and reasonably safe. There's no amount of new homes they could build that would revitalize Houston's downtown because it sucks. Most of the people I know who live and work inside the loop go out of their way to avoid downtown. I live adjacent to downtown and haven't been there for anything, including events, for years.

[BenFranklin100]

A reason downtown Houston may “suck” is because there are too few homes and thus it becomes a wasteland on the weekends and evenings. Mixed use districts with high density of residential will draw in stores, nightlife venues, and restaurants. It will also drive demand for bike and mass transit.

Moreover, there are many urban downtowns that don’t “suck’, such as Boston and NYC that are still facing a challenging commercial real estate market. Additional residential in this metros will be quickly snapped up and drive demand for nearby offices.

[bombcar]

Downtowns have been revitalized and saved, it's quite possible and there are examples.

Often it involves something like building a stadium or convention center or other attraction, which makes dwelling units nearby desirable.

San Diego's gaslamp quarter is an example.

[fragmede]

Where is Detroit in this example?

[bombcar]

Making Cleveland look good.

Detroit's problems aren't locational, they're otherwise (as can be seen by the cities that are (technically) not Detroit but right outside it doing pretty well.