Umm I don't really post here but I play UU so I'll throw in my 2 cents. This is exactly my opinion -- Kingdra is a dangerous Pokemon because you don't know what it's going to do to your team (you send out a special wall predicting a Draco Meteor and it uses Substitute, you send out your physical wall out and it uses Rain Dance, etc), but it can't really punish you for your mistakes with only base 95 offenses. Just one turn of setup isn't going to cut it unless it's the late-game and you're severely weakened, though if you do misplay after that the games likely over.I suppose it's time for me to express my thoughts on the subject.
Here's the thing, Kingdra is one of those few Pokemon that when I first see on the opponent's side of the field gives me that "ugh I have no fucking clue what to switch to now" feeling. The reason for this is simple--unpredictability. The fact that Kingdra has the typing, movepool, and balanced offensive stats to hit hard from both sides makes it really hard to switch into. Obviously, if you know its set beforehand you can just go to your Cobalion to beat Dragon Dancers or your Snorlax to beat Rain Dance / Specs sets. The problem is, you don't know--it's not like Kingdra hangs a sign around its neck saying "hey I'm going to Specs Draco Meteor!".
That being said, it's my opinion that Kingdra has all but one of the traits that would usually push an unpredictable Pokemon over that 'broken' line--immediate power--the trait that broke Salamence in DPP OU. Unlike Salamence's Draco Meteor, Kingdra's wont outright demolish everything in its path, so you can switch your say... Slowbro into it and won't outright lose your physical wall (granted, Rengenerator helps a ton).
I could have probably used better examples throughout but I honestly can't be fucked to do so at the moment. It really is that simple to me, though, Kingdra just lacks the immediate power that would otherwise break it. It also doesn't put too much of a strain on teambuilding because while it has no perfect switchins, there's a couple Pokemon that can switch into all variants semi-reliably (think Porygon2 and Slowking). On top of that, due to the way battles actually play out, you can usually afford to play around it until you figure out its set and then go to a proper check (although I guess this is derived from its lack of immediate power).
So yeah at the moment I'm definitely leaning towards no ban. I could still change my mind but that seems unlikely.
I don't think it's ban-worthy because while it has the tools it needs to be broken, it can't take advantage of them with its offenses. It's definitely even less of a threat once you figure out the set because you can just send in your answer to it straight away.