A lot of games have methods for giving worse players a chance to still have fun - as you said, Mario Kart bends the rules of luck, CoD has deathstreaks, some games have configurable handicaps, but the key thing that is shared between them is that they give occasional boosts - they don't give bad players a permanent advantage. That just leads to bad players winning, which influences their stats so that they are seen as "good" and lose their bonuses, whereas those who were beaten unfairly using the bonuses are then given an artificial advantage on top of their natural one. The cycle repeats. Also, it's hard to calculate how much of a "boost" each player should get in a server with many players of different skills on each team.
+1 for good intentions, I just don't see it being at all workable. Some people are just bad.