I'm confused why they keep buying more reusable bags when they forget to bring some. if I forget them, I usually just put the groceries in the cart unbagged and bring em out to the car, where I usually have the bags and can procede to bag, or if I truly have no bags, just put the groceries in the car bagless.
As a second option, my state eliminated plastic grocery bags at checkout, and instead offer paper bags for 10 or 15 cents a bag, which seems like a good option for those who forget sometimes.