Nothing needs to be fixed, because nothing is 'broken'
For those of us who prefer RP or friendly encounters there is Mobius. It is not 100% grief free..but as close as you can get oustside of SP.
Open play is a free for all, it was designed to be that way, and I doubt the Dev team care to change it. Why would they?
As far as griefing goes...ED is a kiddies tea party when compared to EVE. I put many hours into EVE trying to find a way around the mindless player killing morons, and eventually gave up when ED outstripped it in every way that matters.
I agree that playing solo is fairly drastic..I still enjoy friendly encounters and tipping my hat to fellow pilots..but we have groups like this that deliver a good mix. If solo was the only option and private groups did not exist THEN we would have a problem, but right now there is no problem.
Trying to force a way of playing and rules about player behaviour in OPEN is not the way to go. It's Anarchic by design. You either take the rough with the smooth or you bail and go SP or here..to the loving embrace of Mobius.