Right, no. Fuck that noise.
Blaziken was completely broken beyond reason. Just because he got a handful of new checks doesn't mean he was OU worthy, in fact he's even more broken thanks to Baton Pass. He's #6 used in Ubers for a reason.
Shadow Tag is a fucking stupid ability and everyone knows it. Gothitelle jumped from abyss of PU to BL when it got Shadow Tag. If it makes shitmons like that so powerful, what did you think would happen, when Gengar on steroids got it?
M-Khan was not just powerful, it was the wrath of God. I don't know, if you were around for the Khan mega, but every viable team was Khan + 2 counters + 2 counter-counters + Talonflame. I am not kidding. A retarded monkey could beat a skilled player if it had Khan and the better player didn't.
M-Lucario was not as unreasonably strong, but it was unpredictable as fuck and still could alone 6-0 whole teams. It's a Choice Band Terrakion with a Choice Specs Keldeo and a Starmie strapped to its back, and that's only unboosted. Also you can't revenge it because it has fucking three forms of priority.
It's debatable whether Genesect not being there made the metagame worse, but imo it deserved to go too. It was not the be-all-end-all of revenge-killers, but it was basically Cheap Momentum: The Pokemon. If you think of Genesect as a scarfmon, you're probably going to lose because it's really not. Eventually it was going to get unreasonable, so why delay fixing the meta?
By the way, all the megas are not getting banned. The only thing even remotely worth suspect testing is Pinsir and maaaaayybe the Charizardites. Everything else is either completely balanced or shit. I still think Thundurus and the rest of the Deos need to go though, they're cancer to this meta.