I use the player list to find out where people are and contact people not on my scanners or not in the same system as me.
(I know that I will PM Beyond.the.jumphole if seen in-game, or a respective player faction of the faction my independent is representing in order to get invited into group chat.)
However, asking for information as to the affiliation of people on the list is pushing the meta-gaming too far. (This is an opinion, feel free to set your standard as you see fit.)