Clearly, "huge disaster" was a poor choice of words. The important bit in my statement was "compared to Morrowind and Daggerfall".
If you make a list of what was good, or interesting about Morrowind and Daggerfall, you'll see that pretty much what was good about those games was deliberately excised from the design in Obilvion, while a lot that was crap about them was kept or exacerbated. They also added new features that failed to improve upon the original design in any way, and in fact made the game worse. All this sounds a lot like a disaster in game design to me.