No we don't need a pve. Here's why; everyone would gang up on the mobs making the high valuable loot easy to obtain, once they have that then theyd come on the pvp games with all the pimped out guns and kill everyone with lower tier weapons. Making it a crappy, sweaty game. The current system is fair. Single player is almost like team play besides the odd rat. Team play is always pvp.
Honestly, this game isn't designed for those people who think everyone deserves a gold medal in a race. There are winners and losers. Thats just a fact of life. Its great for those of us exposed to the real world and understand it. Go play some other feel good solo game if you want to live in La La Land.