Andersp:  If it is seen as a problem that higher rated players don't want to play
against lower rated players, then one solution is to improve the
ratings system.  The BKR system penalizes higher rated players harshly for playing against lower rated players.  A properly designed ratings system should not discourage higher rated players from playing against lower rated players, as the BKR system does.  Of course, the higher rated players should always prefer longer matches.