Maybe they should tell them right on the phone that they will be billed for the rescue and do you still want us to respond? Maybe they'll be like the other kids on the Auto Road and decide they can get out of the woods on there own or just deal with an uncomfortable night and walk out at first light. Appealing to money seems to be one of the only ways to get through to people.
"Hi. This is Dan with 911. I can dispatch a SAR team to find you. It's my understanding you aren't properly prepared with the 10 essentials, is that correct? You're estimated rescue cost is $7,600. Should I have the team get started or are you capable of waiting until morning to walk out?". (Yah, I know that would never happen nowadays. If anything, SAR would get sued for having the audacity to tell someone it costs money to go get their negligent ass out of the woods.)