There's no accounting for taste, or so they say. It turns out, there's no accounting for the benefits of investment in the arts either. On the surface, "support for the arts" seems like one of those universal aspirations, something no one could be against. But it's not so simple.
While a community may agree that some public artwork brings benefits to everyone, those benefits are not equal to everyone and may even be negative for some. As the now infamous Maplethorpe fiasco exhibited, art is subjective, and when we publicly subsidize it, we inevitably please some while offending others. This is important because any art that is worthwhile challenges the appreciator, but the public vehicle forces people to subsidize things with which they may wholeheartedly disagree - it's presumptuous to think policymakers and bureaucrats are capable of choosing "good" art over "bad," or even meaningful art over vapid.
Despite cries of the arts being "woefully underfunded" in this country, private investors have for centuries patronized artists whose work provided some benefits to themselves and consequently to others who did not pay for it. This is the nature of ideas, and government should not be in the business of interfering with this process. As this RAND study points out, insofar as public policy can motivate the arts, it is from cultivating interest (demand-side) rather than simply building more galleries and performance spaces. This is important to keep in mind, as more and more cities get into the business of broad-stroking their way into the arts.