"Eve Online" must be doing something right, I mean it exists for many, many years now. Maybe there can be learned something from there.
In Eve you have 3 different zones - High Space, which is pretty secure (though you can still grief there, if you want, just with high penalty). Then you have a "Low Security" zone, and then you have a "Null Security" zone, where everything is allowed (rules there only are player-made).
I stopped playing Eve a couple of years ago, but until then ofc they hat the same type of discussion there, too, between PVP and not-PVP players. But in the end they stayed with all 3 zones, they did NOT completely abandon the safe zone.