Both Jon and Karyn agreed that their lives would be easier if they were in charge. And with a simple wish they were. But the kind of world they created wasn't exactly what they imagined. Of course, sometimes that's how the stone worked. Not that it twisted the wishes, but the stone had its own interpretation of the wishes made. It didn't always do what the wishers meant.
So when Jon said "I wish that me and Karyn were in charge," the stone interpreted it by making them ...