Always people so quick to call "CONTRADICTION", but whatever.

You have to see it this way, and to see this you really have to look at the big picture. The long term, essentially. To save the mess that was 1.X he had to go with something the was safe, structured and known to be successful. He needed a foundation. Can't keep trying to make something from out the blue. Yoshi's plan thus far has been using the simple, and functional mechanics that WoW has established. They are easy to understand and learn and this creates a gate for a fresh audience. He needed something that was going to make money. And from here, he can tweak and tinker, adding and changing things. Obviously you don't go for a suddenly radical shift. Slow and steady. So it's going to be long termed process.