Exploring isn't necessarily that bad of a thing, granted some of the dungeons are rather small and pointless but for the most part exploring a dungeon is the same as exploring the wilderness. The only major difference would be that there are probably more enemies and that you are more or less forced along a route. For the most part many of Skyrim's dungeons are pretty unique even the computer generated ones are decent enough.
The same can be said for Fallout, though in my experience Fallout has less dungeons (locations where you actually enter) and more open locations.
And I am pretty sure Skyrim has more locations than Fallout 3 and New Vegas (not combined).
Then again it is all user dependent, each player's experience is going to be different based off of how they play and all that. So for me grinding through the dungeons that don't have a unique reward item to them is still just as interesting and fun. As for you it may just be pointless grinding.
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