Why would you say that...

Yi doesn't require any aiming at all. He has one point and click button. He's extremely powerful for almost no effort. So yea

Nasus requires quite a bit of competence, unlike yi. Most people don't have the patience to play Nasus at all, let alone the skill to land his abilities.

Katarina is just freelo. But at least requires some competence. Much more than playing yi does. You can be bad at playing katarina. It's hard to be bad at playing yi unless you are trolling or a new player trying to jungle.

He takes less skill than either of those champions.

lolyup. 10/10 play for free wins