All they need to do is remake Morrowind, the entire province of Vvardenfell WITHOUT level / loot / enemy scaling of any kind. Oblivion was bland and Skyrim was blander. I also truly despise level scaling of any kind.. let the player decide and learn where he can go and what he can tackle. Games like Morrowind and Gothic 2 did this awesomely.
Oh and no fast travel, make it so you unlock travel modes as you play (like in Morrowind with the Boats, Striders, Mage Guild Teleports, Gondolas, Propolyne Chambers... add spell crafting back and make the game harder... besically, de-casualize and de-consolify the latter games..
Unfortunately, it is all about the dollars and Bethesda knows they need to cater to the lowest common dominator