As someone who is anti-Chandelure, here's what I have to say.
In DW, it's not as good due to the dominance of Sand. Hell, the June statistics had Tyranitar at nearly 80% usage in the 1337 stats. However, in regular OU, Choiced Tyranitar got massively nerfed due to Tornadus-T, and Sand is nowhere near as dominant because Excadrill is banned in non-DW OU.
It's not that Chandelure is unstoppable, because it's very stoppable. It's that the metagame is so centralized around Chandelure that if you want to win, you are practically required to run Tyranitar, hence why Tyranitar is so god damn high in the 1337 stats. If you thought Scizor's 1337 usage in OU pre-BW2 was insane, think again, because Tyranitar's usage is even more insane. In my case, I do not want to be forced to run Tyranitar on every single team I make just to win. It's like how back before Excadrill was banned from Standard OU, Excadrill could be stopped, but you were required to use Pokemon such as Gliscor or use your own weather just to win. When almost 80% of DW teams in the 1337 stats run Tyranitar, and you basically must use Shed Shell on anything defensively oriented (such as Skarmory), you know something's wrong. Chandelure is the reason I don't play DW much, and as soon as it's released, I'm just going to quit OU if it doesn't get banned because I refuse to use Tyranitar on every successful team, especially since Tyranitar is even easier to beat now.