I don't think I'm entirely sure what you're getting at, here.
It's not as much the compression as it was the absurd amount of similar looking clutter for the sake of detail, and the implementation of landmarks that annoyed me in Fallout 3.
Specifically, this. What do you mean by "similar-looking clutter?" That they've hand-placed rubble and such from a limited selection of pre-modeled pieces? Or...
And what's the problem you have with the implementation of landmarks? None of this is a direct arguement - I just honestly am not sure what you mean, and need some clarification.
The theme park world of Fallout 3 killed much of the experience for many, not just myself. For some more so actually. The game world felt like small and inane "theme park" for lack of a better title than a large and sensible wasteland.
This, I might agree with you on some points. Bethesda in general makes what I tend to think of as "theme parks." But I'm not sure I'm using that term in the same sense that you are. (Or maybe you are, I don't know...)
It struck me at some point during Fallout 3 that essentially what I was doing for a large portion of the game was moving to a (rather wide, admittedly) variety of "fun houses." In that you go into a place, see the sights, have some stuff jump out at you, etc. But you're basically there to see the panorama that's been created. This applies most aptly to most of the dungeons in the game (and before people jump on me about this - they're very good "fun houses," and I rather enjoyed them. It's just how I feel about experiencing them.) But also to most of the towns and quests, ec.
Back to topic - I'm not sure I can picture what you have in mind in terms of wanting more of a "wasteland." It sounds good on paper - but I'd be curious to hear what your idea of that sort of game would look like in terms of gameplay, etc. Because to be honest, I felt pretty good about the scale and size of Fallout 3. It wasn't so small that I felt terribly confined (it was rather more densely-inhabited than most areas in Fallout 1&2, but that can be explained easily enough and wasn't something I had a problem.) Nor was it so large that I ever got bored just walking from place to place.
Frankly, no matter what's settled on for Fallout 4 I'll be happy so long as I never, ever have to (or feel the need for) an auto-walk toggle. If I have a need to set my game on auto-pilot, then I might as well go make a sandwich or something while I'm waiting - and game design that gives me impetus to get up from the computer is never terribly good game design.