I think the idea just boils down to a popularity contest. As stated no one can have an effect on the game itself, only an effect on the players around them. Someone who is an 'Idol' to a few players, can be totally unknown to many others.
In my short time here, I can think of only one character who has had an impact on a majority of the inhabitants. My character has never been to one of his events but knows how sucsesfull and popular they were with all the other characters he has met. My character did however emensly enjoyed the auctions this dwarf put on before they were squashed by a *&^*&$#&^#$#$@#%@!$%&, and I know others enjoyed them aswell because of the turnouts.
I can see honouring someone like that, who created situations for all of PS, not just a certain group of characters but all characters.
But that in itself is what I find popular, so it goes back to my original thoughts.