I don't think it's that bad. I mean it's just an off day, what other day would it be? Oilworkers are abused yeah but I still think that it's fair to have one day off on Sunday. I'm not religious in any way, shape or form but I still sit around and do nothing on this day.
I haven't heard of any law when businesses aren't supposed to be open on Sundays...but still, there's gotta be an off day and Sunday is a good day because it prepares you for the start of the week of work.