As I said, its an 'opinion' - what you may consider a 'better looking' top that isn't a 10-top for example may not be what the 'grader' considers to be a 10 top. Not one of my Cores are 10-tops and yet I consider many of my tops to be more aesthetically 'pleasing' to my eyes. I don't really like super 'even' flaming thats consistent across the whole body - It looks as if they could almost of been drawn on with a ruler and the same width Sharpie - I like more 'character', more 'natural' variation.
Therefore I too may see guitars that aren't 10-tops but for whatever reason, I actually prefer it to many 10-tops
This guitar for example isn't a 10 top - maybe because the Flame isn't super consisten and/or even across the top, but with the growth rings and flame, I think it's far more 'interesting' and unique. You may think its one of the worst top you have seen and only a '7' at best - but that would be 'your' opinion, just like someone at PRS decided which pieces of maple were 10-tops and therefore we as Customers would pay a 'bit' more for.