Being that it may be true in some cases, it does not mean it's true in all cases. My guild has been constantly recruiting the entire tier, but the majority of people we get seem to be ones who thought Dragon Soul was hardcore raiding because as soon as we hit Thok and Blackfuse, they started to drop like flies. Clearing spoils before the holidays, it took until January to get Thok. Yes, that means the raiders who dropped were obviously not cut out for it, but that does not cover the core 15 or so people that are being held back by the 5-10 that can't cut it.
As for the OP: SoO isn't getting old for me. I run my heroic progression and an alt 10 man with my guild. Granted, once I have it on farm, I might get a bit bored of it, but we do need to get 25 people a mount off of Garrosh. I like to change it up by playing two rather different classes (Prot Paladin and Prot Warrior).