Wow. I'm honestly flabbergasted. Thanks for letting me know MarieWoodell...
But what the? The more skilled you are, the bigger the reward... I don't understand!
It's unbalanceable, thats the problem.
You would either have people with low Attributes gain really a lot from finishing a mission (like form 20 to 60) in order for people with high ones to see any change at all, or people with high Attributes would gain nothing.
The 1 point for all is not perfect but sadly its the only way to do it i think.
The only way to make it "fairer" is to start restricting mission access or set different objectives according to the related skill.
Like
01 ≤ Agi ≤ 20 = Kill 100 Snable
21 ≤ Agi ≤ 40 = Kill 100 Argo
41 ≤ Agi ≤ 50 = Kill 100 Feff
51 ≤ Agi ≤ 60 = Kill 100 Atrox
....
91 ≤ Agi = Kill 100 Prot Stalker (not sure if Maturity works for the quest yet else Prot = hardest not unique to a LA mob you can imagine)
This would be for the same mission with the same story to it and the same reward in this case to gain 1 Agility. (The mob choice is not perfect i think but thats just an example).
Not allowing people with either too low or too high Attributes to do a certain mission that has Attributes gains as a reward i think would not be a good idea.
For other stuff like the hinted on quest items that will follow i find it ok.
A high level player wont need the very low level L item that you can get for killing 100 Argo, as long as he will get a similar option within his/her skill range like killing 100 Osse for a high level L item this would be the way to go imo.