Sure, Kyu-B might be able to match Kanga with Outrage, but Outrage is quite frankly a terrible horrible move to use in a metagame with Aegislash and Fairies and crap running around everywhere to ruin your day, so saying "Kyu-B has a stronger STAB" is honestly a worthless argument since it is forced to rely on weaker means of attacking (namely, using weaker STAB DClaw and running Special attacks) to kill things.
Well, first off, I just want to say that I was referring to gen 5 Kyu-B, for the precedent it shows of not simply banning something because of the power it posseses. Gen 6 Kyu-B is a different deal altogether, and one which I personally refuse to even comment on, cause, for all we know at this point it now gets Icicle Crash and Close Combat. Either way though, the comments on Kyu-B are solely related to power. Yes, Kanga has other things like you mentioned. I don't deny that. I am simply saying that power itself is not really a reason to ban things. Its how it effects the metagame, and simply listing calcs of all the things it can beat is not, and never really has been a good measure of if something is broken.
As for the other stuff, again, I'm not saying that Kanga does not have a ton going for it. I was simply attacking one section of an argument. Frankly to me the fact that it only has to change one move is kinda irrelevant since it is still changing, which is the important part. Regardless though, it was that part of the argument I was looking at, not that plus other stuff.
And basically, as far as good checks, I think the point is exactly in what TFC said above: "It seems to me that people haven't been running all that they could to stop Kanga that would still be relevant in the metagame....I expect better players to ladder when Suspect starts and that...is when this adaption would happen. It's easier to make this decision in a better environment." Or, in other words, I really can't necessarily say at this point because we have not really had the time or effort put into it to really figure it out.
(Also, for the record, 252/252+ Gourgeist-S is only 2HKOd ~20% of the time by Adamant Kanga Crunch [though what that is with the factored in chance of Def drops I have no idea] so that is a significant risk for Kanga to stay in against, even if it predicted and Crunched on the switch as it is risking a burn.)
EDIT @ Treecko: It seems we are using practically the same calc for different purposes. Personally, though, I don't think it makes sense to talk about how it might KO, after rocks, if and only if it predicted the switch and used the only one out of the four of its moves that the Pokemon is not immune to. Rather, I see the fact that it needs to predict, and even then can't nab a guaranteed 2HKO as a win for the opposing Pokemon. Also, for what its worth, without Stealth Rock, Jolly will never 2HKO and Adamant will only do so 21% of the time. Either way though, this is just one calc and not exactly relevant in the grand scheme of things.