Instead of talking justification, isn't it more a question about what kind of game this should be? What made everyone start playing Genesis, and what is keeping people around? Is it the ability to play a role? Immersion into the RP? Is it the unlimited growth? Grinding your heart away on a script? O...

I would suggest going back to what was, and possibly take it a bit further. Remove mortal levels from the game. It doesn't really add anything, other than something to achieve. Make the highest stat lower than what it is now. The old system was fine. Old immortal was around new epic. Without these, ...