It seems that people are complaining because the game has freeform PvP..? DayZ has the exact same thing. Player choice is what makes DayZ compelling. If you arbitrarily restricted PvP, you would lose much of what makes the experience compelling. If you don't like getting killed by other people, you probably shouldn't be playing a multiplayer game that tries to simulate the zombie apocalypse (or any post-apocalyptic scenario).
Not saying that WarZ is good or anything, just that complaints about PvP in this kind of game are silly.