I think the laws are kind of goofy, but at least in this region where it seems like a lot of people go to church on Sunday, it makes slightly more sense because it allows more people to be there.
That being said, those religions whose followers worship on Saturday (or any other day of the week) don't get any special accommodations, so I think we should let businesses be open or closed on Sunday as they see fit. Or any other day of the week.