It's a PvP zone, when you enter the PvP zone other members of the community reserve the right to PvP with you.
You consent to this when you enter the PvP zone.
Orsinium is a PvE zone, players can go there and harvest v15 and v16 materials all day long, providing they pay for the DLC.
If it's not broke don't fix it. It's possible to farm 5k+ stones an hour if you're playing half asleep in AD, DC and EP sewers in extremely low traffic areas. It's such a non issue it's ridiculous.
Why is it a non issue?
All mobs in IC give insane experience points when compared to all mobs everywhere else, they drop trophies which sell for 600 to 1,500 gold, TV stones which can be used for materials and 800 stone potency runes which sell for 6,500 [fast sell] and 7,000 gold.
Participation in Imperial City gives insane benefits when compared to anywhere else. You can just decon crap and sell the mat for 500 - 600 gold too.