^why don't you just let them know? they're clearly asking why
say it is because the packaging is less then stellar and the items arrive not in the perfect condition it should have
otherwise they'd think you're a fast reader and just out to buy, read and return (or buy, xerox copy and return if you're not a fast reader)
If the item arrives damaged due to the packaging, Amazon would probably expect the buyer to ask for an exchange/replacement item, rather than an outright refund. I know Amazon has some issues with sending books, since their boxes only come in certain sizes and they don't do a good job of stuffing the boxes with packing material to make sure the books don't get banged around.