I remember the "AOE-Combo" metagame before Riot ended it. I didn't really see any problem with it, it was actually kind of fun and it's not like it was completely impossible to counter. You wanna counter an AOE team? All you needed was a Gragas or Janna ult, both of whom were extremely powerful champions at the time of this "metagame"..
No offense intended to Riot but it's almost as if you're having so much fun in your offices you don't put that much time into balancing the game. It seems like you just take what people say on the forums and a month later implement it into a patch. For example, when Urgot first came out right from the start people complained he was UP yet it took you what, 7 patches to give him any form of buff?
Now it seems as if you're just nerfing anything and everything that noobs complain about on the forum. You're taking the skill component out of League of Legends by doing this. In all honesty, all these "ridiculously" OP things people complain about never seemed that bad to me with the exception of a couple such as the "run away from xin zhao" phase of the game and the Leblanc release (good hotfix though I must say).
Basically what I'm trying to say is this.. Rather than nerfing every single thing that some noob on the forum says is OP because they don't take the game seriously enough to read the situation and counter it, simply implement different things into the game to counter them. Give champions their own uniqueness back.
For example, nowadays in ranked gameplay many people find Cho'Gath to be a poor choice just because many tanks have more to offer than he does and are more reliable. In beta Cho'Gath used to have his own unique quality where his ult could kill enemy Tryndameres in ult and bypass Chronoshift and Guardian Angel. If this were left in the game it would give people a reason to play Cho'Gath, because he has his own unique quality to counter Zilean and Tryndamere.
Rather than nerfing everyone to the point where the game is balanced to an extreme where all things will simply do a set amount of damage, slow, stun, or things of that nature give people a way to counter other champions through their champion choice so when people get fed up by getting owned by too many Insert Champion Name Here they can just counter them with a different champion next game.