I can see why many people will dislike this movie. It's a bit slow if you're looking for action rather than atmosphere, many details are left unexplained, and what is explained comes way out of left field. But I felt the bizarre and unexplainable events only added to the creepy atmosphere of the cold wilderness. I actually found myself wishing the filmmakers had left even more to the imagination, as the underlying explanation seemed to cheapen the rest of the movie somewhat. I still found myself quite satisfied when the credits rolled, but I think a more ambiguous ending would have been a better fit and given this movie a more lasting feeling of horror.
So while not without its flaws, overall I felt it was a much more interesting movie than its current rating would suggest. It reminded me of YellowBrickRoad, another creepy and bizarre wilderness horror with widely divided opinions.