Dio, there are significant changes in the game engines between TES games on top of the delay between iterations. Even if it were a valid comparison, it would be a case that the devs don't mind giving you their tools because they already know they will always have better tools and the bigger sand box (even if the community is more creative). Could you honestly say that with the dev team for BF? Sure there's some upgrades and shiny features, but the differences between even BF2/BF4 (not to mention 3:4) are almost negligible if you remove the destruction physics/visual updates. Could you say the same for Morrowind and Skyrim or Oblivion and Skyrim? While not leagues apart, each iteration brings quite a bit more to the table in comparison.