The 4/16 path about EXP is stupid!

I am an  American Tier 5 CA player.

Before 4/15,when i got 54k damage and 2 sunk in a game, i got S rank.

But now, i only get B rank!!!!!!!

The new reward system is stupid!

how can you let such a Tier 5 CA make more than 54k damage? Is the rank system fair??