The purpose is to pay them for their work. They worked 20 hours per week -- it's like a part-time job.
We looked at past themes, and the further we went back the cheesier it got. Someone threw out legends, and that instantly grabbed us.
Our goal was to cut out the cheesiness. We spun it around into a show to watch.
Some groups would struggle to make five minutes, so they'd put more randomness in the act.