Bosco,
I don't know how others feel about it, but for me, you are buying the book, not the case. I like it when sellers note cracks, because those could be to the point where, if they get worse, they could threaten the book. For scratches, it is what it is, a scratch on the case. To me it does not need to be disclosed and is not the responsibility of the Seller.
I mean this very respectfully, but also truthfully: If you came to me with a case scratch problem, I would politely tell you to go pound sand. I'll be interested to hear what others have to say.
--S.