True as that may be, Skuddy, population numbers speak for themselves. The development of the pop count on retail also shows things as they are. "Better" MMOs having come out at the same time is an excuse, not a reason. A true WoW player wouldn't leave the game for another. They would leave it because it's drastically different to what they want and expect from Warcraft. And that's exactly what MoP did. If Notorious wants to blame someone, he can blame Blizzard all he wants.
On a side note, I loved early Cata and I'd give much to see the Cata realm restarted. We had a discussion about this in my guild on Outland last night and pretty much everyone agreed that pre-DS Cata was the ****, and said they'd go to Cata if they could get a fresh start. Of course, this is not possible because it will piss off all end-game geared players on the Cata realm (I even forgot its name by now) and because opening a new progression realm is not feasible (I guess).