Statistics aside, what really bothers me about Shen is that he's always been a garbage-ass ninja. The taunt/vorpal combo made more sense than whatever that new kit is. The sword area? The sword at all? An entire two skills that are neither direct CC nor damage... Yes, Shen; Annie cares about not being able to basic you.
She does. And while you're at it, champions with actual stuns and slows probably don't care that you have, what, 15% of their health if you land all three of those hits? Mmm...
It's just that if they spruced his kit with damage he'd feel more like a ninja, but they're so glued to these backwards images of champions. Shen shouldn't be summoning anything to battle, he should be entering the fight and turning the tides with a clever initiate. He should have ways of shedding the damage off for periods of intense focus and his teamplay should probably be in that ult; everything else should be a little more focused on making him good.
Kalista's the same thing, where she's become so reliant on having a composition that makes her ult work well for her. Just to be able to play with the same level of interaction that other champions get naturally. They keep gutting her, because good teamwork makes them shine a little too well. Which is fine, I think, because they're pretty goddamn mediocre as it turns out otherwise.
Shen's so specialized it hurts. He's built and scales like a tank, though, so there's really just nowhere to entirely fit him in. Coupling that with the level of CC literally any class is carrying nowadays and it just feels like he's a bit too stoppable, I think. There's no point at which he can really command a fight with good play; if he can do it, chances are literally any other tank would have had half the trouble and twice the payout. Even Rammus is working with more resources, and two of his skills cancel each other. Yikes.