What's everyone's issue with Kalista?

Her win rate at Plat+ is only ~48-50%. No different to most champions in the game. As someone who has played her a number of times she doesn't feel that strong unless she gets going early - as is the case with any other AD Carry in the game. Even playing against her isn't all that frustrating with the likes of Vi, Malphite, Wukong, Ahri, Katarina (the list goes on), which are all popular and strong right now, that can effectively deal with Kalista in most situations.

In fact, most of the time if Kalista gets through Bans in Solo Q I hope someone from the other team picks her because every one I've had either lost lane hard or (at least almost) threw the game. Considering there's no lane swap meta in Solo Q, Kalista has a pretty rough time against the likes of Graves and Corki in lane and during the mid game. I'd even go so far as to say that she's only really effective in premade teams or under the same kind of circumstances that a Vayne might become a monster.