An educated guess:
No giant robots, talking trees or settlements consisting of kids on shrooms.
So "EPIC!" stuff and "wacky" stuff is imaginative?
Erm... Sure, but imaginative=/=good.
Weren't they suppose to have a clan of talking beavers in FO1?
That's on par with Little Lamplight IMO.
Offtopic:
But yeah I fail to see what was so better about the main story in FO3.
It had one of the longest and most painful tutorials ever.
Then we're off to find daddy which is basically Go to moriarty, go to three dogs, go to Li, go listen to soft-porm, go save him from epic time-capsule vault, drag your ass all over the [censored] PP, get attacked by evil people in (Oh this is shocking!)
dark armor, be Li's [censored] for 20 minutes, get a GECK which turned from a couple of papers and some seeds into a wonder machine, get abducted (Originality here), escape (more originality), watch a [censored] transformer have all the fun with Michael Bay explosions all over the place, anticlimactic boss battle, the end.
So we had:
* Talk to X
* Rescue daddy which we have no emotional connection to from an evil maniac in a time capsule machine in a "cool" sepia world.
* Roleplay as a plumber for a while.
* Fight evil guys in dark scary armor.
* Find good guys in white armor.
* Fight evil ogre's.
* Get garden of contradiction kit.
* Watch transfomer have all the fun while explosions are surrounding this "epic" character.
I don't see how this is better than NV's story.