What's wrong with making fun of Pottery?
Is it any sensible way to establish a moral code, just because some bright-eyed attention-seeker bumbles around doing good deeds, all on the pages of a Book?
Nothing. Last time I checked, J.K. Rowling and her fans aren't insisting that one live by the precepts of Harry Potter, demanding tithes, tax-exempt status, killing in the name of Harry Potter, or branding readers of other books as 'heretics.' Some works of fiction are enjoyed for what they are. Others lead to cults, such as Christianity, Islam, Scientology, etc. They are free to believe it but don't impose it on others or insist they are provided special treatment because of their belief in fiction as fact.