Heroes are remembered. Those who give their lives are ingrained in our hearts for all eternity. However, it is often more beneficial, while perhaps more difficult, to continue living for one's family, community, or country. Death brings a simple end for the loyal soldier, while survival entails a complicated road ahead.
Those with power are by default the bearers of choice. The mighty cannot stand idle. The fate of whatever world the Spartan enters rests upon his shoulders.
Many believe that Noble Six gave his life. What they don't remember is that Spartans Never Die.