The purpose was to encourage the people that wanted to do PvP to kill people around their level, and if I have the opportunity of attacking a lvl 40 or a lvl 55 I'll chose the lvl 55 (assuming the same class), because I'll get honour points from it. But if the low level people are attacking XR I won't hesitate to kill them, as they are part of the team that are Raiding, killing them weakens the team and gives us an advantage.