If Males Up Until F5 (Fifth Generation Away from the Serval) are Sterile, Why Would I Need to Neuter a Male Kitten?

Although males may not make viable sperm, they still produce the male hormones and will exhibit male (tomcat) behavior that makes them undesirable as pets in the intact state. For example, they will still spray and mark their territory and be continually searching for an available female to mate to.