That's a completely different scenario from releasing MOP without raids though, that's gating to keep people from diving straight into raids, not releasing the game early because your raids aren't done. While I don't particularly dislike not being able to jump into raids instantly, I don't like the principal of releasing an expansion without raids.
I also wouldn't call the karazhan attunment length, iirc it was two or three quests outside kara, followed by Shadow labs, Steamvaults, Arcatraz and BM. You can argue there were other steps (like Black Morass attunement), but if you were interested in raiding, chances were you were going to have run the instances that "attune" you to the 5mans already.
You could easily do that in a few hours with a guild group.