Scoring has nothing to do with the number of terminations you make. In the three games, you were the third player knocked out of game 1 which gives you 6 points, first player knocked out of game 2 which gave you 8 points and the sixth player out of game 3, which gave you 3 points. Giving you an average of 5.66
You could have won that last game and still not finished in the points. Some players did win one of their games and didn't finish in the points.
Getting knocked out of two games first and third will generally not give you a good enough average to finish in the points.
You needed an average of at least 4 to finish in the points in the Chinese GP.