I don't think I know what rider switch is then. Someone waits with the person that isn't riding. Then the one that waited rides by entering the LL queue. It requires someone not riding in your party.
Are you proposing that I ride with my daughter while my wife waits outside and then I ride with her after my initial turn? Wouldn't that cause more of a wait for others? That's two people in standby and then two people in the LL queue when the three of us could have just gone through once on DAS. And what about my daughter? Who watches her while I ride again? She could ride but that is three people in the queue for a total of five added folks in the line, four of them riders, while DAS would have yielded just three riders.
But then someone would have physically waited in the line which is really all you want.
edited for clarity.