how many people here who are up in arms about kalista have actually played her before.

Played her.

Problem with her is that she can be fun to play as (I personally didn't), but not fun to play against. Notice I said as, not with. I hate supporting Kalista, especially since Kalista mains are less likely to tolerate a roaming support (which is sometimes necessary past laning, a support is a team's support, not a babysitter past laning). She's not too difficult to counter, but she's just one of those annoying champions. It's like Master Yi, or Nidalee. Not exactly overpowered, but has a frustrating playstyle to play against. Granted, it's rewarding (and great for stress relief!) to finally land some good, hard cc on them and have your entire team take a crap on them.

The only reason I tolerate Kalista's existence is that I can shit on her in bot lane.