PvP is fine, its meant to be brutal and cut throat, adding in a switch where people can just ignore other players would be the worst possible thing dayz could implement. Zombies are hardly a challenge for a competent player, other players are the true danger. taking away the danger the other players present would make this game stale as hell, way more predictable and just ridiculously easy to gear up and roam around with top tier gear forever without any true threat to your mortality. The game is a PVP game people just need to get it through their heads and deal with it.