If the effort:reward ratio is an issue, then wouldn't it be solved by scaling rewards depending on how close you are to the point goal for victory?

So if it takes 1000 points to win, getting 700 points by the end of the match would give you 70% of the rewards. It would encourage people to play to win without excessively punishing lower skilled teams, it would also turn people off slacking because you don't just get free rewards for sitting around the entire match.