Sure, I understand the legal arguments. But I would note that NAMBLA's writings, similar to what's in this book, specifically led some molesters to molest young boys (by their own testimony). So, it's quite rational to presume that this book will do the same. If there's a record (which there is) of such promotion causing men to sexually molest boys, then reasonable people in a reasonable country, if they cared foremost about the welfare of such boys (which in our country they do not), would use all means to prevent the promotion of such. On the moral plane, Bezos is no better than a sexual molestor himself for marketing the promotion of the sexual molestation of boys. He is likely to be actually responsible for the sexual molestation of boys which would not otherwise have occurred. At the base of it, I believe that when the law (by whatever principle) causes innocent boys to be sexually molested, there is something terribly wrong with the law and the country which writes it.
<sarcasm> And of course we can trust the testimony of criminals to be totally honest and in no way self-serving or rationalizing or making excuses for their crimes, right? </sarcasm>