Who says hes great? I don't think I've ever seen any real praise for him at city. Not only that, but hes still rotated a lot, it's hardly like he has a cemented first team place, and his only real competition is kolarov whos been one of citys most underwhelming player.
Hes decent, and a good passer who can support his team pretty well, but hes not aggressive and doesn't attack as such. Hes just decent and thats all people tend to view him as.