0
I'm not particularly fussed either way. If its about grocery shopping then there's shops open if you look. The local IGA is open til 10pm 7 days a week. If its about retail shopping then think of the pennies being saved while the shops are shut.
It would suck for tourists who come here for a holiday, from somewhere where the shops are open until later. There's only so much to do after 6pm in Perth if you dont have family or friends here.