I think it's due to the fact that everyone is playtesting Skarbrand since it was released. It'll take a while for the best deck to emerge and for counter decks to appear. It's not the worst case of being overpowered, I take it you are unfamiliar with pre-nerf Destruction in the first season (until Onslaught gave everyone more tools to beat it). Death and Order are not very far behind Destruction and Chaos, and very little difference in performance in the hands of a good player.
What faction are you playing? I find it very useful to play all the factions to better understand their strengths and weaknesses (although, I confess, it took me a while to find a Destruction deck that I enjoy playing. I have now, but I still don't play them as much as other factions).
It's also a good idea to test your decks in Campaign mode or against the various challengers that pop up from time to time. I think you will find Chaos not as overpowered as you first thought.
Well, you certainly have more experience than me at this game. I get beaten in ranked a fair bit, mostly by Order and Destruction, and I had always put it down to being beaten by better players than me, but from what you've said, this shouldn't be the case, maybe I should file a Bug Report every time I lose a game. Play Fusion should really go ahead and pop me into at least Diamond rank because "Chaos"! Am I rite?
Seriously, while Chaos can do 21+ damage in a turn, it doesn't do so consistently, Order, Destruction and Death are much more consistent decks that don't rely on the right blessing at the right time to win.
Now, off I go to grind my way through ranked the old fashioned way, since, as we all know; Khorne cares not....