I went 6.5 too. I mean, I can't speak for the hundred or so people that went 5.5 or lower, but there's clearly some odds and ends going on with the book... bits of splitting visible at one or both spine corners, the paper loss at the bottom corner, the BC stain, and (ironically) the *top* staple appeared pulled-at-best, detached-at-worst. Even without knowing the bottom staple issue, reasonable enough to think the book was 'a near miss of Fine' or some variation on that.
I've only noticed this discussion on this page, I put 6.5 as well after grading on the tablet. It's immediately why I posted when I awoke to the big monitor that I thought I too had over graded. I thought 5.5 made sense then just because I remembered similar books like that in this contest, similar to a piece missing out of a cover of a otherwise very nice bok. A 1st brainiac book comes to mind, although I don't remember why.
I didn't notice a staple, nor did I read the notes. Although it looks clean from here, although I new I had over graded on a lot of them, I was dreading by how much but 5.5 makes sense