Faxanadu - Maybe because most people work Monday-to-Friday and maybe even Saturday, so they'd need to go out shopping on the Sunday.
People, like me and my family, who are Athiest (or any religion that doesn't have a sabbath day on Sunday) may want to go out for dinner, or even pick up some milk and bread.
Hell, even King Henry VIII believed that the English man was getting too lazy, and made it law that every Englishman went archery on a Sunday afternoon. And he was a pretty big Christian (read: Church of England, a founding of).







