Fairness tends to be the core principle of any point-buy character creation system. You give every player the same number of points, and so long as the game is well designed each character will be equally capable; or at least appropriately capable for the choices that the player has made.
The scholar-athlete may be a strong, well rounded character, but he cannot out study the pure scholar or out perform the pure athlete. It’s not a perfect model, but it is ultimately fair – especially for characters at the beginning of their career.
Book of the Neglected 