If you mean the training edicts, then it's because when leveling up, you do not want all stats to go up equally, you want to specialize in one primary attack stat (Agi usually considered the best).Is there a specific reason why full save doesnt have all the eddict points skills up? Such as some points make the game bad or too easy?
And after you're max level, those expensive edicts only give you +5% to stat, often just one stat point.