I think there are a lot of filler characters that aren't worth the time, lots of 50-60 hour chars that didn't make an impact. There are a few notable characters that haven't died yet so there is that. I also think that the majority of players cycle through characters to quickly to actually make connections which basically leaves the threads empty for only the characters that did live long and accomplished a lot.

Also, it seems like some of the more long lived character begin to fade out near their deaths and stop logging in as much which by the time their death comes means they aren't giving much screen time, thus they fade away from the memories once they die.

This is sadly due to an older player base with responsibilities so meaningful connections aren't made and aren't remembered because of that.