Start of WotLK can hardly be called "during WotLK", that's like saying slurpy is an overall good drink judging only by first sips.
Mind your tone will you? Here are the facts:
What exactly happened in 2009? Whole Acti-Blizz merger and casual direction mess. Now ask yourself how would it be if the blizzard kept updating like it did but kept it philosophy from start. LFD/LFR with consequences for bad behaviour, same for CRZ, Telling players to simply man up and conquer the content just like in TBC? Somehow the subscriptions kept rising during those dark cruel times. How is that?