As I understand it, it is meant to generate within each employee that desire to innovate and do their respective jobs better - not merely to meet the requirements, but to exceed it. Your salary is what you deserve for meeting 100% of your assigned tasks (whether reasonable or not). The bonuses and salary increments are what are given to you, if you are seen to be doing above and beyond your pay grade. With the bell curve, it creates a competitive atmosphere where "above and beyond" isn't the sole determinant, but something that is judged in relation to your peers.