I distinctly remember myself and others arguing since at least late TBC that giving PvP gear overgearing to some people ruins gameplay. The reasoning is that it's not PvE that a group of people progressed against A.I. mobs, but it's actually real live people in front of you in PvP. It comes to reason their skill should be King, it should the predominant factor of what's going on, not their gear, i.e. how long they've been grinding.
So why did it take them so long to make that change? Were they wrong before? Did they keep it as something to incite users for the hype of a new expansion?
I doubt that they were simply wrong. Then again it's hard to know the full reasoning. They might as well be wrong now too about this, we all do mistakes.