"Other reviewers suggest the main story plus quests could take 80 hours-plus to complete, and who has that sort of time?"
Um...the people who bought the game. And you don't need to do EVERYTHING; you could probably finish the main quest in about 30 hours
Sigh, this is why newspapers shouldn't review video games. No s*** it's too intimidating to the gamers looking to buy the new Harry Potter game; it's not a casual piece of crap Kinect game