I think it's one of those games that isn't necessarily for everyone. I can imagine complaints about the world being barren and there not being a lot of things available to do, but personally, all of those were strengths for me. It's a very restrained, minimalist/artistic experience with a fantastic sense of scale, mood, and art direction, and a simple and understated but perfectly revealed narrative that is most effectively communicated through game-play (unlike other game narratives that just alternate between unrelated game and movie footage, which kind of annoys me). Every moment is just damn satisfying, without any unnecessary fat.
I've always wanted games to be more like this and less like the way that they tend to be, what with their massive online, open world, ultra-customizable, addictive, achievement-unlocking, crafting and foraging, real world economy, twisty-turny, choose your adventure whatever.