I don't want to die. If you are a player you are a threat, simple as that. It is a survival game, and whether or not I survive depends entirely on keeping you from me. The risk of being friendly is much greater than the reward.
That's your own opinion. My opinion is that the game would be boring without having a human target. Its the thrill of the chase, the giddy feeling of walking up to someone's remains and wondering what goodies you will get today. Chopping woodpiles and building houses? I've been doing that for 3 years on Minecraft, and if that's all you want to do I suggest you go play that on peaceful mode with some friends. If you absolutely want to just build in peace then go as far into the wilderness as you can. There are places where you won't be bothered, but if you do expect to chop regular trees, because me and every other person who is ready and able to take you down will be fighting for the right to the good materials. In survival games you can either survive or thrive. Surviving is easy, but if you even plan on thinking on thriving you must be willing to take risks.
So I take it the idea of 2 getting twice the work done in the same amount of time is new to you...