The point here is that not all car users are making the choice to drive based on what is better for them. Many are using their automobile as a class signifier. "I can afford to drive and park my car in NYC". With parking costing as much as it does it is an outward sign of wealth for many who drive their car to work. It doesn't necessarily save them time or money and so isn't necessarily "better" for them in any way except as a class signifier. This is to be discouraged. What percentage of total NYC individual drivers these people make up is not known by me. Probably not by anyone else either but I bet it's significant. My guess is that these drivers are a primary target of the proposed system but one that goes unspoken because class issues in the US are too messy to discuss openly.
John Thornton