The list are a simple means for people to create and maintain an almost personal auto vote system. One look at my delegated to list lets me know who is currently active, and who is not, and then I can adjust delegation. I have decided to leave the people on the list even when I end the delegation, if they were good enough at the time to get a delegation, then they are good enough to continue to help support.
Thank you for the mention, and mostly for helping spread the word of one usage of the list function on PeakD.