Sammy G, you obviously have no idea what you are talking about as evidenced by what you said about this profession. Let me enlighten you as to why someone would actually want to be a sex therapist, more specifically, my own reasons for wanting to enhance my clinical training by obtaining certification as a sex therapist.
In the past, I have worked as a domestic abuse and rape crisis advocate. I have a B.A. in Psychology, a Master's degree in Clinical psychology, and am presently working towards licensure for private practice. I am currently employed by a state approved agency and work as a therapist providing therapeutic services to both children and adult populations. I provide individual, couples, group and family counseling to families who are involved with the Department of Family and Children's Services. This includes children who are in the foster care system. I assist these individuals in working through issues related to being victims of domestic violence, sexual abuse, emotional abuse, etc.
That being said, these traumas often have negative effects on these individuals' lives (both children & adults), including anxiety, depression, development of unhealthy interpersonal and intrapersonal relationships, and they often exhibit poor communication skills, and have symptoms of PTSD.
Unfortunately, a history of sexual abuse/trauma may led to an individual (child or adult victim) having negative/unhealthy views about his/her body, have low self esteem, and hold negative ideas about sex and intimacy (not just the physical act of sex). Victims of trauma may also not be able to engage in sex/sex acts which may impair their relationships and it is not uncommon for them to avoid any type of intimacy all together. Therefore, wanting to become a sex therapist has nothing at all to do with having difficulties in my own personal relationships or sex life, but is more about serving the needs of individuals and helping them to led healthier, happier productive lives.
The certification as a sex therapist will serve as a type of specialization in counseling in treating issues related to sexual dysfunctions (which once again is not just about the act of sex, but also related to difficulties with intimacy, depression, anxiety, and/or poor communication, etc).
To put it another way, the add-on certification of sex therapist to a clinical counseling degree is analogous to a medical doctor who decides to specialize in cardiology, plastics, orthopsychiatry, pediatrics, urology, etc. You get the idea. Hopefully, you have a better understanding of an individuals possible motives for wanting to specialize in the treatment of sexual disorders/dysfunction. If not, perhaps doing some actual research on this type of training will improve your knowledge and expand your viewpoint on this profession.
Also, those individuals who choose to be counselors/therapists do not do so because of selfish motives, such as wanting to have an advantage over others. As a matter of fact, this profession is one that requires actually the opposite, requiring the therapist to be attentive, patient, empathetic, and to distance themselves from their own personal problems. All of which are not characteristically qualities a selfish individual exhibits!
It takes an emotionally stable individual to do this type of work, and those who are not most likely are not very successful in their careers and probably have very few clients.