How about a PVP zone gamma that just will not allow the attacking of structures? No turrets obviously, but all other MPC stuff, terraforming, etc can be built.

Then you get the excitement and thrill of transporting in and out and mining while exposed to risk. But the safety knowing your sandcastle won't get kicked over in the night. That way there are still some risks involved, but not the all or nothing we currently kinda see...

I suppose hell camping and Logoff traps may dissuade the casual gamma person. But the thought of losing a bot is a lot less worse than of losing your gamma base.