Thought I would put my opinion in here since I believe I've experienced both sides.
As a fresh spawn, I get killed a lot. Not because they are afraid of me, but because they expect me to be a douche. Which will be explained in a bit. See what I do is, I stay away from everyone as a fresh spawn. I loot small areas where I know I will only find newbies too. Every time I have attempted to interact with a group, I die. But half the time a geared guy happens to loot the same place as me spots me, I interact by saying "hey man I see you have gear, but I have nothing of use and I'm willing to give you some ammo if you let me go". Most of the time they will take the ammo and let you go, buy I'm bit stupid to give them ammo they can use against me. Even if they did, I would have been dead anyway.
And the other side of the story.. As a geared guy in a group, my team members are very PvP orientated and their excuse is " all this ammo but nothing else to do with it". We must have well over 2000 shits between us. Zeds are not a threat. Wildlife is a joke. Players are the main threat. There is no incentive to play together. As a geared guy in a group, fresh spawns will try to interact with you and half the time they will try to get a weapon to shoot one guy and loot him, to then try and kill the rest of the group. Never works out for them, but they try. When I'm on my own, I can't interact with fresh spawns either, because they will try their luck at getting my gear. And if I ask them to stop following me, they will see it as a request to try and kill me. Which then leads to me having to waste shots on a guy with no gear. Now I just shoot at anyone because they aren't willing to cooperate and they won't interact anymore.
Now if there were limit supplies of weapons and/or bullets, and we couldn't dismantle them, I would use traps and hand weapons. It wouldnt stop the KoS, but it would reduce it. It would allow players to interact a bit more. If the zombies were the main threat and food/water was scarce, people would team up to survive.