I believe ratings and feedback are a lot more accurate then like/dislike. There is barely any accuracy in if a game is good or not if its like or dislike. Because maybe a game is in between.
There will be a "like" button as such for posts in the forums and game comments i believe when AG3 is launched.
The "dislike" button will not be there at launch however is being taken into consideration. Scan the forum thread (i think) to find the subject on it, there was some differing opinions.