Where does this narrative that Bethesda games have never been graphical showcases come from? Going all the way back to TES:Arena and Daggerfall (for all of their bugs)- they were pretty damn amazing from a graphical standpoint compared to their peers. Morrowind was also a huge step up as well compared to its contemporaries (really only Gothic was remotely comparable). Oblivion looks insanely rough now but at the time there were tons of "yes, this is really a screenshot" type posts. Vanilla Skyrim running on a PC was looked great on release as well.
Fallout 3 is really the only kind of "Eh" game they have put out graphically.
It's mostly about perspective. Their games can look impressive in places when people are subjected to fairly new visual tech and novelties they're not yet familiar with. Like the water shader in Morrowind, which could make up for stuff like the character animations which I flat out laughed at when I first saw them. Oblivion was also the introduction to distant LoD for many people, but I just noticed how shoddily executed it was since I had seen other games implement it more tastefully years before.