How much parking is too much parking?

The conventional wisdom is that parking requirements are based on a worst case scenario; namely the day after Thanksgiving and the following Christmas shopping rush. Follow the link below to see pictures of parking lots and garages on Black Friday last week.

Storing cars is very expensive. The only thing more expensive is building parking spaces to store cars and then have them never be used. What a waste!

Can you imagine Wal-Mart building an entire row of their store and then leaving the shelves empty? It would be ridiculous. Why then do we simply accept that large swaths of their land would be built upon for a use (parking) that literally never happens? We accept it because that is the price of entry, the cost of complying with local regulations.