when i played Star wars galaxies there was no PVP or Passive servers. Everyone joined the game in PVE mode. if you 'declared yourself' either rebel or imperial, you entered a PVP mode in the same server, and had a tag over your head.
You would see the PVP'ers all running around killing each other, while the non PVP'ers did their thing, all in the same space, side by side and everyone was happy.
Groups and areas formed where PVP was very active. The same thing happned with the role players who found their own cities and planets to play one, all in the same servers. Yes occasionally paths crossed and you would get the immature type who got stiffies over killing roleplayers (who had to declare to wear the allegence armour).
Then in the middle was the mass majority. Those who went about their business crafting, doing missions, grinding etc. Most people would dip into pvp or roleplaying at some point but it was never forced on you, either way.
It didnt happen overnight and i felt it got really balanced after 6 months once all the idiots and kids had got bored and moved on to other games. That left just serious players. The PVP'er who were left were 99% a great bunch. They would respect the roleplayers and vice versa.
I genuinely wish GTAO turns into something similar as thats the type of MMO im looking for, but currently we are in the pahse where all the kids feel the need to flex their pubescent tiny muscles by griefing others