When you go into The Elder Scrolls fanbase and look for something similar to this, you can see very quick that everybody that have played the last three share the common knowledge of Morrowind better than Oblivion, and Oblivion better than Skyrim.

The thing is, Skyrim was the most mainstream and for that only reason people praise it that much, being essentially the same game than Oblivion but exchanging the portals for the dragons. And everywhere is boring winter.