Until they start spot checking and handing out the $5000 per day fines in the law. And no, the store is not allowed to sell plastic bags separately or give them out for free.
Perhaps the stores can have a plastic bag "g'mach" to be distributed by some sort of dispenser belonging to an organization "unaffiliated" with the store...
Interestingly, in the communities where it's being ignored in the big apple, even supermarkets that originally were enforcing it in the beginning, have stopped, and returned to the good ole' system.