Many experienced players know most hosts(not all) host game for friends. While having friends as teammates does not guarantee you a sure win, it's good to know that someone is willing to co-operate with you to win the game, that is why many serious players(like me) like to go top. What left for the Scourge? Bunch of easy going players who just want to have fun feeding, or some 13-year-old rage kids. Of course, this is not always the case(i've seen some friends playing together, feeding together, and leaving together), but the probability is high enough to create the 'let me top host' situation.