I always rate games but I sometimes rate say 0/10 and later on start to like the game but I can't change my rating so I think that Armor Games should have an option that lets you change your ratings on games.
I think acmed is right... but you chould never rate a game after playing it for 1-2 min. You chould rate it after a 10 to 20 min. trial, or once you know 100% that's what the game desevres
if you want to see people that rate and don't play, check out the ranks board on the home page. Not the top 100, the current leaders. OMG talk about taking AP too seriously.
But the actual answer to your problem is: there will be a change rating ability in AG3. Period.