Basically they had a lot of abilities that weren't fun, and a bunch of stats that made the game suck. Most people were going to Ask Mr Robot to figure out which piece of gear to put on, and Icy Veins to figure out what button to press when.
They needed to carve out all the old cruft before they can add the new and exciting back in. I was equally cynical when the shattering happened, but after a few content patches was quite happy with the change.
This is a common gripe but I fail to understand it. I've been playing since BC and I never found it "fun" getting my gear hit-capped, or watching gear drop that wasn't useful for anyone in the raid, or having skills I never used.
There is tiny chance that I might play WoD but I don't get the time to play WoW as much as I used to get in my college days.
But if you are really sure about playing, I would be more than happy to join you.
Edit: I'm only playing casually.