The Devs make the Savage content first, they love to do Savage content, and they only make normal content to pay the bills. If they didn't have to feed the normies, I have a feeling it would be all Savage, if not Ultimate level.
This is where WoW did it better, they made normal first, then upped it for the mid-tier raiders and lastly cranked it to the max for the hardcore raiders. Each tier was well balanced, fun and could stand alone on its own without trouble.
