Well, first of all, it would promote abnormal and unethical sexual ideas. People might start to have warped views about the human body and sexual relations. Secondly, it could be extremely offensive to a large number of people, causing discomfort and harm to their mental well - being. And finally, it would violate the general moral and ethical standards that society has set up for literature and media, potentially leading to a degradation of the overall cultural environment.
The existence of such 'detachable genitals erotic fiction' would be highly detrimental. It would disrupt the normal perception of human anatomy and sexual health. It may lead to a desensitization towards inappropriate and abnormal sexual content, which in turn could influence people's behavior and relationships in a negative way. Moreover, it would be a stain on the literary and cultural landscape, as it goes against the fundamental values of promoting positive, healthy, and respectful expressions in art and literature.
If such a thing were to exist, it would have a very negative impact on the psychological state of the readers. It can distort their understanding of normal sexual and physical concepts, leading to abnormal or inappropriate thoughts. It also goes against the values of respect and propriety in society.