i don't think the ninjas in konoha actually realize how strong itachi really is and i don't see why they should, except orochimaru. they know that itachi is considerably strong, but i think only orochimaru knows how truly strong itach is because orochimaru wanted itachi's body and i'm guessing orochimaru did a lot of research on him. but all the ninjas know about orochimaru's strength since he's been around 33+ years longer than itachi and he was one of the sannins. i just think that the ninjas don't know enough about itachi and how much he has grown, skill and strength wise.