I know the plot's not very complicated, that's part of the problem. It's kinda hard to tell it from the sidequests, and the majority of the time you can look at the screen, ask yourself "why am I doing this thing on the screen now?" and not really have an answer. Then try to figure out what you're supposed to be doing instead of being in the middle of nowhere, and whatever it is is not much different. In a weird sense it feels more non-linear than either Fallout 1 or Fallout 2, because you really feel like you could at any point be anywhere doing anything. On the flip side, it all feels like doing anything makes about as much sense, so if you don't like one thing you can't really go do something more fun as most of it is about equaly as fun (or boring).
Achievements really did something for it, though, there's a sense of direction when you shoot for them which helps things out a lot. I think part of the problem is that most things you can do in-game are not very rewarding, or rather, that the rewards are not very meaningful. Like in-game, I mean. The loot is mostly pointless, trying to carry most drops is pointless, a few spells are clearly better than other ones, XP is kinda slow to come by... So when you combine this with the general aimlesness and kinda breezy excuse-plot there's a strong feeling of "What am I doing?"
Cloakwood, for example, feels unrealy tacked on and filler. You're there "because plot" except "there" is just a bunch of nowhere like the 20-odd bunches of nowhere you've allready been to (and some of those were more dinstinct and memorable) and there's barely any plot going on. And then what's at the end of it is more mines, except also less memorable ones than the one's you've allready been to for no obvious reasons. Really, I met these two guys on the road, they wanted me to go to Naskhel and instead of doing the Friendly Arm Inn like the plot wanted me to I ended up on the other side of the map doing what seemed to be a completely random sidequest... Which turns out was exactly the same as the main plot. How bizzare is that :D You go do something with two complete goofballs in order to NOT get caught up in "ye boringe olde maine queft", something that looks like a 100% foolproof sidetrack, but no, by some miracle that's what you were supposed to be doing anyway. And then after you clear the bandits - NOPE, your bandits are in another mine, past another stretch of the ass end of space, much like the one you've been trekking through to get to the first mine and then the first bandits.
So first the main plot is the same thing as a sidequest, and then after one mine, some woods and a bunch of bandits... you get to go through some woods to a mine full of bandits. Mind actually blown, that's two different ways of making whatever you do feel the same as whatever else you do or did. I kinda found it all fun this time around.