A lot of the comments here even prove the point. People are so bad at yuumi they don't even realize how bad they are.
https://na.op.gg/summoner/userName=Auberaun Auberaun, one of the yuumi playtesters, is 22-2 on the champion. No flame here, but Auberaun is not that insane of a player. The champ is just good if you know how to play her, which most people don't. Because they don't even know how suboptimally they play it.
Yeah he's not that insane of a player, can confirm