We need to leverage density, skill, and knowledge to propel further innovation, economic growth and development (lord knows our economy needs it), and at the same time we have to build new institutions, new strategies, and a new urban social compact to improve the lot of those at the bottom.
Density has costs and benefits. Richard Florida is proposing we maximize the benefits and minimize the costs.
Macroeconomic forces encourage density. Already, we are seeing tremendous benefits from urban agglomeration. The costs of density are the problem. Real estate refugees from cities such as New York and San Francisco are a good indicator of the ailment. Where business packs in, residents flee (if they can).
How do we better manage urban agglomeration? This is a task for planners and economic development professionals. Instead of another initiative to attract/retain talent, solve the density problem.
That last sentence is editorializing. I don't know how Richard Florida would react to the suggestion we put aside efforts to attract talent. However, he is clear about attacking the density problem.