I think people are more pissed about the "Getting a wrong idea about BDSM" aspect than they were about the "This will cause binding rapists" thing.

Personally though, my only real issue with the book is basically how it causes almost every girl to gush over what is essentially an abusive relationship. It seriously makes me question if most women either have fantasies of being abused, or sincere caring relationships are just so rare that they can't tell the difference between a caring relationship and an abusive one.