I honestly don't know. Apathy is an epidemic. I have had this conversation with parents of children who don't carry and adults who don't carry for themselves. I've tried being reasonable, educational, visual, and very rarely used scare tactics. Honestly, the best trick up my sleeve is the Allerject (Auvi-Q) demonstration. People seem much more receptive to the new technology and it's more convenient size. I think I've had more success with that than anything else, oddly enough. (I even mention to women and girls that they fit ever so nicely in the waistband pocket of their yoga pants, which makes them less of a burden to carry. Though some of them carry phones in their bras, which I think is gross, but I suppose Allerjects would fit there too. *shudder*)
Still, it's not something people want to admit to, and not something they want to carry. All we can do is educate as much as possible. They have to make the choice on their own.