So, I'm going to go off the top of my head here a little bit.
In August/Sep, Space Wolves won the NOVA Open 6th Ed; foot Dark Eldar, screamer/flamer Daemons, mix-and-match Necrons and Sisters all came exceptionally close to being the winners instead
In October, Grey Knights won the Battle for Salvation 6th Ed, against Eldar in the final; Tyranids and old Chaos placed among the highest, with Nids as 2nd Generalship
In late October, Daemons won the Feast of Blades 6th Ed, handily
In November, Grey Knights won DaBoyz GT, with Tau/Eldar at 2nd, pure CSM at 3rd, and Cron Air as Best General
On the same day in November, Orks won the 11th Company GT (all of these events are at least 64 players, btw, and nationally or internationally attended), over Tyranid in the final
Can we please stop freaking out about the game being broken or needing comp? Good players win with good lists, and every codex can put out at least a good list or two with that codex as the Primary Detachment.
What needs to be understood is that people will still always choose to take extreme builds in 40k. Extreme builds are much more difficult for some codices/lists to deal with, and much EASIER for others to deal with. They are a gamble, and it's INHERENT to Warhammer 40,000, and always has been. Just as Draigowing and Nob Bikers and other lists were natural gambles in 5th Edition (while lists like Strakenguard and Coteaz GK were more natural "balanced" lists), screamer/flamer spam and Cron Air are gambles in 6th Edition.
Certain tournament formats also ENCOURAGE GAMBLING, which isn't a criticism. It's just natural that the points level, mission format, scoring systems, etc., all contribute to what lists are slightly better or worse (note: slightly, these things only impact the game but so much) over a given weekend. If taking a loss but crushing a bunch of people is rewarded, people will take gamble lists more frequently. If winning is winning and it's not valued beyond that, you'll see less gamble lists.
Either way, understand please that a) a HUGE variety of codices are performing well AND winning at the GT level already into this edition, and b) No matter what you try to do to the game, nothing will ever stop people from bringing list STYLES that suit them - big crazy swing for the fences rock-paper-scissors gambles, or all-comers balanced builds that trade max battle points for min losses.
I'm not prone to all too many list-build "this is great and you're bad" articles, but I'd happilyrespond to e-mailed requests with lists that can tackle all of these types of gamble lists at a tournament (or go toe to toe with them). Just understand that 6th Edition is still the wild wild west ... your local playgroup is NOT the be-all and end-all of what's good and not in the game ... and there's a MILLION ways to play a game that's by nature heterogeneous. There isn't one set points level by game design, there isn't one set army build per codex, and now there are literally dozens of competitive "codices" due to the allies system.
To give an explanatory strawman here, by the way - if I brought a guard list with nothing but as many flamers as I could possibly afford, I'd TOTALLY WRECK an ork foot horde without vehicles. That Ork player might come out of it going "there was no way for me to beat that list!!!!" Well, true. But no one would claim it's a good list, because there are a ton of bad match-ups for it. The same is true to an obviously lesser extent for some of the extreme builds out there right now. Points levels only impact WHAT the extreme build is or may be. One way or another, if someone brings a hammer to deal with any problem he runs into, he'll seem ridiculously well-equipped if he only runs into problems he can solve, but will instantly fade into obscurity if he goes up against a problem he CAN'T solve with just a hammer. Toolkits are always relevant and useful, but less flashy and less overwhelming when they work. Yada yada.
In short, internets, chillax ... the evidence is mounting that you're WRONG about certain codices or armies being unbeatable and/or totally broken ... and yeah, I'm specifically looking at anyone losing their mind about Daemons or Cron Air.