To be fair, the main thing Bethesda has on their side is the way their engine is designed, allowing to iterate a metric shit-ton of content at a very rapid speed. Making a new quest point is as easy as slapping together a character model, typing up some dialog, adding it to the map and quest journal, and off you go.
(Being facetious of course. It's not as easy as all THAT, but you get what I mean.)
Designing original puzzles takes time and resources. Iterating a number of DIFFERENT puzzles from one 'puzzle type' takes far fewer.
What they MIGHT have done was to have two or three 'puzzle types', and then mix and match between them. And those feedback-starved "I've pushed this button six times and I still don't understand what it's doing" abominations in the Dwemer ruins don't even count as puzzles. At least they look neat.
But frankly, I'm not complaining. This is just how Beth operates. I'm sure their next game -- be it Elder Scrolls, Fallout, or some other IP altogether -- will have some slightly-evolved version of the puzzles we've seen in Skyrim. And then there'll be some NEW feature whose lack of depth we'll grumble about.
But we'll keep buying their games
