Notice the lack of parking. Yes, this shopping center has failed.

Parking is always a necessary evil for any successful development.  Whether it is a shopping center or a neighborhood.  Someone always has a problem with parking.  Sometimes there is far too much parking, sometimes there is not nearly enough.  Most people in the development industry subscribe to the mindset that if a place is perceived to not have enough parking, the place is successful.  I happen to be in the group that believes this.  The following mandate in one way or another how much parking that a land use should have:
1.  Land-use Codes and Subdivision Regulations:  Codes and regulations are the most restrictive mandate on parking.  The way that today’s codes and subdivision regulations are written across the United States, lack of parking is not an issue.  Most codes will require X amount of parking per X amount of square feet/ tables/ beds, etc.  There are a few places that do not have these requirements, but very few.
2.  Bank Lending:  Bank lending, especially in the current economic environment, plays into the equation for parking as well.  If a developer desires to create a shopping center, restaurant, etc., the developer needs to provide a certain amount of parking to satisfy his/her lender.  Typically the banks are not quite as restrictive as the municipal codes, but occasionally they can be more restrictive.

On-street parking emanates activity and success. Without cars, would it appear as if the business is poor or non-existent?

3.  Needs and Desires of the Customer/ User:  Even without formal parking regulations or the need for lending, businesses or offices are still going to provide parking to support the needs of the business.
My preference is to not have the stringent regulations that a governing agency puts on development.  If the governing entities want to regulate parking in some manner, it should be regulated with a maximum amount of parking.  We should allow the lending agencies and the actual use mandate the needs for parking.  The results are going to be similar, but with this methodology we may end up with less unusable surface parking and greater cooperation between parking users for shared parking.