I'm fairly certain this location of SAQ has no interest in making money. Case in point: they closed early on NYE. Also they are open only until 6pm on weeknights, which means I can barely get there before they close when I get off of work. After a full day of work, I'm sure most people could use a drink.
SAQ pretty much has the lockdown on liquor and wine in the city and they have plenty of variety. But it's apparent that the employees have no desire to be there when the doors are locked and the gates are down at 6:01pm. Yeah, it's downtown, but would it really kill them to close at 7?