It's like this. No one is asking for anything to be 'modded'. It's been proven that people will go out of their way to ruin other players game experience. You cannot combat griefers. Griefers will simply exploit game mechanics to get free, cheap and risk free kills (heck they even annoy true PvPers).. Remove friendly fire and you automatically cancel out 90% of complaints - it's a mandatory component of a PvE mode.
Delusions with well rounded rational arguments for, and a strong community to back it up. No one asking for a true PvE ground to unite a large part of the player base is delusional.
Well or not, Fuel rats exist, player groups that are profit free do exist to help other players out.
The only invulnerability being called for is against being stabbed in the back.. which I think is perfectly reasonable for a PvE mode

If Thargoids are indeed an incoming PvE hurdle, and I can see possible 'mankind' vs Thargoid CGs.. I see PvE modes becoming fantastic community get-togethers.. what better place to be than to face this new exciting challenge.