What are you talking about?
I've been playing Runes of Magic, which seems to me the same free-to-play but pay-for-extras model, for a month and none of the things you say happens, happens. All of my interactions with other players have been civil and mature. I've never played WoW so griefing may be common there but since it doesn't happen in Runes of Magic, a free game, your theory goes out the window.