The game engine gives bad ratings to MCs because they play badly...Its another thing that the game engine is such that MCs generally play badly and are involved in maximum of COUNTER-ATTACKS...

I have had MCs who consistently gave good ratings and at time my team never got counter attacked...There are MCs like this but they are HARD to find and are a rarity...

I have recently bought a NORDEUS generated MC who is a beast and is getting very good ratings......