So you equate harassment to having drinks poured over someone?
The whole point, which you seem to fail to grasp, is that words on the internet don't hurt ANYBODY. A drink can stain clothes, cause physical harm if the glass contacts the person, and generally cause real tangible damage, unlike online harassment.
When you ignore someone in most online games, that is the end of it- they no longer have any contact with you. If you happen to be playing a real PvP game, maybe they can continue to attack your character in game, but that is the whole point of the game.
If you don't want other players to be able to attack your character, don't play a PvP game, this is basic common sense 101.
Why not just go with "be nice to people"?
Ah yes, what a solution.
Why stop there? Lets just say "don't break the law". There we go, I just solved all crime! Nobody will ever commit another crime because I just asked them not to.
In seriousness, the problem has been explained to you repeatedly and you seem to be too dense to understand it.
"be nice to people"
Male gamer asks a female sounding gamer if she is single, response: "WTF, ASSHOLE, I DON'T WANT TO BE HARASSED, GET THE FUCK OUT OF THIS GAME AND LEAVE ME ALONE!"
Female gamer asking male gamer the same- very difference response.
It's impossible to be nice to everybody when different people react in different ways to the exact same thing.