I hate to say random people just going around and killing random people just to be annoying isn't griefing, that is just normal play. I can go on any other MMO with PvP and do the exact same thing, murder random people just to be annoying and for "shiggles".
It would be griefing if I followed you around and kept killing you over and over, making it so you can't play the game. Or another good form of griefing which I ran into (there is a thread about it but not by me, i was just there when it happened). But a cmdr was ramming ships in a station and killing them, while not getting any wanted level, or fines for it.
Though I will agree they do need to make the punishment fit the crime. Why would I pay a 50mil bounty when i can just go get killed and pay 15mil and be clean and clear. Any other MMO I have played that didn't reward or promote pvp to the point you get rewarded for it, the crime fit the punishment. But in saying that I don't want pirating to completely leave the game, so they have to find a way, to balance it.