Undead Rogue sees little kid nightelf playing with his sword in Westfall having the time of his life. If I didnt then go and lob his head off, well, I'd be no Undead Rogue at all would I? I'd be a bloody little fairy is what I'd be, and nobody in Undercity would ever speak to me again, therefore ruining my gaming experience.
I do draw the line at coprse camping people who didnt start on me first though. That's what you call griefing, ganking someone then moving on is not griefing.