I totally get the idea, but when a company can easily fire you for no good reason it's hard to develop any real attachment to a job so that it is something beyond just an exchange of labor for payment.
Most employment contracts in the US (sorry for the US centric bias, I don't know where you're from!) are at-will, which means either party can walk away at any time for any reason. That doesn't stop us from forming deep friendships and relationships. Its the human condition.