I think the constant reminder that reusable is the only option probably injects the idea of just carrying your shyet into the collective consciousness. To what degree I don't know, but the few times I've bought one of those reusable bags I just never used it and brought a backpack or opposable thumbs next time.

By the way, does anyone know why a lot of shops on the east coast will bag single items? I went to a CVS to buy some sunscreen and they put it in a plastic bag without even asking if I needed one.