SL-Mark: I think to obtain rating 2500 you have to defeat player 2100 in your first game. And it is not so easy. Formula adds 400 pts to opponents rating if you win. If you win later, your rating will be smaller. In case of huge differencies you earn nothing from your following victories.

Yes it is frustrating, but if player with such huge rating isnt good he disappers or loose some games in future. If he is good, he wont hide and will defend his position.