I would imagine it's the same problem you have with '71 Topps baseball cards and '85 Topps football cards. The black borders are so condition sensitive, they practically chip if you stare at them hard enough. The number of quality copies worth submitting are probably just plain fewer and far between. That said, I'm still astounded a cover is enough to drive the popularity of this book so high. I've been monitoring raw copies of this on eBay and it appears to sell really well even in lower grades. Admittedly, I really like this book and the fact that the story and interior artwork is rather blah, it's one of the few books that lends itself to slabbing real well as you never miss what's on the inside.