I rarely play adventure games because I suck at them.
IMO: Is the maze an integral part of gameplay? As in, are you supposed to get lost? In FO3, I don't think they were intentionally going for it, since you can mark stuff on your map/radar. Does "solving" the maze give you a reward? Nope. At least I don't consider "This metro stops wasting my time...until I have to get to the other side again" a reward (and there's usually more than one between you and your objective).
That's not a challenge, that's a chore.
And part of the issue is that they still look alike.
Now if they weren't mandatory or would look more diverse (for example, the metro under a park collapses and the radioactive plants overgrow the place) to get around in DC, that would be a different story.