For starters, this is more than a game. It's something like a very fun simulator or experiment with game theory as one aspect. The very nature of this game being a true sandbox means the players themselves will determine where the game goes, and what constitutes game play. It is about rebuilding a society, using the tools and resources available to us. Tribal warefare will be part of the game, and some people will concentrate on this aspect. I suggest you find one of those tribes if that is what you want out of the game. Some tribes plan to concentrate on trade, some will become roving bands of Nomads, or entertainers, some will farm animals, some will become political and seek to rule, etc.

In other words, this has the potential to be a serious long-term blast of a game, and the developer has chosen not to hold our hands, or shove us into a certain style of play. Embrace it, and forge your own adventure.