The primary reason I don't play in Open is because the penalty for murder is placed on the victim, not the murderer.
What's the penalty for murder these days? A 9,000 credit bounty? That's not a lot of money, and murderers don't care about the bounty anyway. I lost my Cobra, and that costs me 500,000 credits to get back. That's over 50 times more than their bounty! What if it was my Python? That would cost me 8,000,000 credits to get back. That's almost 900 times their bounty! See what I'm saying here? The crime and punishment system punishes the wrong side.
"So go to Solo or Group." I have, but that isn't really a solution to the problem. Ideally we should all feel safe "enough" to play in Open, and the game would be better for it. In order to get me and people like me into Open there's going to have to be a dramatic shift in risk.
Shift the cost of the rebuy from the victim to the criminal. When a Clean pilot is murdered they get their ship back for free. The Pilot's Federation places a non-expiring fine on the murderer that must be paid upon the destruction of their ship in the amount of some percentage of the rebuy cost of the ship(s) they destroyed. The Pilot's Federation gets their money just as they always have (although in a slightly delayed fashion), and more importantly the victim isn't penalized for being a victim.
I bet at least some of the griefers (or serial killer "roleplayers") would think twice about murder knowing that eventually they'd have to pay some significant percentage of the total rebuy cost of all the ships they destroy. And if they can't pay the fine? Too bad, so sad, bankrupted back to a Sidewinder. They should have thought about the consequences of their actions.