I don't think it would work now as with so many couples both partners work and they only have weekends to shop out and about, not everyone gets on with internet shopping..
Being open both weekend days spreads the number of customers over 2 days. If it was down to one day imagine how busy shops would get - shopping centres often already too crowded.
Also provides work for people for saturdays as well as sundays.
I used to hate sundays when young, places became like a ghost town and you worked hard all week at school then sundays became like a lost day with everything shut.. Might enjoy the peace now, not sure!
Having said that I wonder how much sunday trading has affected how much families meet up and so many live big distance away which makes it even harder...
Agree over old fashioned values though.. I guess every generation has said the same and feared how society will change as boundaries change too. Bad things have always happened in various forms but I wonder if have increased.. we might never know if proper stats aren't kept - they say some crimes aren't even recorded and maybe some people don't report stuff if don't have the confidence that things will be followed up?