Considering this is still going...
A Roleplay is about the community, not the will of the GameMaster. Many GMs will allow their personal feelings get in the way of doing what is right for the community. Perhaps in some cases the GM isn't truly an authority figure, if power has been chosen to be put in the hands of the players. However, the one with the assigned title "GameMaster" will hold the power to make decisions that are ultimately not his or hers to make. Rejecting a player, fine, they didn't fit. Purposely removing a player disrupts the community for the sake of something he disliked. If they were reasonable, they'd discuss it with the player, and if they conclusion was reached that they player could no longer continue, they would leave if they were a decent human being. Beyond that point, they become trolls, a problem for the mods to handle eventually anyway.