Thing is that is usually the bullies themselves that come into the forums and QQ about being bullied by the GMs. Those who like to exert power over others seldom like power being exerted over themselves.
There is a thin line between KoS and bullying. One is a natural function of a game that provides unregulated PvP. It is expected and often encouraged. The other is a personal grudge between one player and another (or several others). The second form is not condoned as a part of the game, but regardless a natural byproduct of a game that encourages PvP interactions. Players get annoyed, hurt feelings and simply angry at certain others and want to exact a little of that optional vengeance. Sometimes it gets taken a little too far, and that is when we need GMs to step in and referee.
Let's face it, if we were all saints, there would be no need of GMs. But the fact of the matter is that Rohan is a game that breeds conflicts between people, and we need the GMs there to keep it from getting out of control.