From Slang Dictionary:
Poser

:
someone who pretends to belong to a group only by affecting the attributes of the group.
Limiting candidates only to those in the top 100 in post count omits some names that definitely belong.
I would suggest that the incumbent be given some discretion: perhaps take the top 90 from post count and give the incumbent 10 wild cards or something like that. Several of the most egregious posers are not listed at all.
I also think that Poser of the Year would be something like leadership of a trade association: once a person has been elected, they are no longer on any future ballots and instead take on an
emeritus status. The idea is
not to "prevent" them from winning again; it is to make sure that "new blood" continues to be rotated into the position.