7.2 is a good score. I tend to think of 7-8 as "very good" and 8+ as "excellent".
Since I rated it a 7, I'd agree with the aggregate; if I were allowed to rate films by decimal places, I'd probably put it at a 7.5, but that's still around 7.2.
My reason? I thought it was a very good mystery/ thriller, but that it didn't hook me in as fully as the top films of the genre. If you think about something like The Third Man, another search for a missing man with sinister criminal plots oozing in through the shadows, Winter's Bone falls far below.
It's got excellent cinematography, great atmosphere, and good performances, but it just didn't stick with me or pull me in as fully as I'd have liked.
"Very good", not "excellent".