Final answer:
A commonly not discussed reason for abstinence is using it to achieve an altered state of consciousness for supernatural experiences, as the usual discourse revolves around health, prevention, and personal beliefs.
Step-by-step explanation:
The question asks for a reason that is not typically a discussed reason for individuals choosing abstinence. People may choose abstinence for a variety of reasons, such as personal beliefs, religious reasons, avoiding unwanted pregnancies, and preventing sexually transmitted infections (STIs). However, being in an altered state of consciousness to experience a greater supernatural reality is not commonly discussed as a reason for abstinence in the context of public health and sex education. Given the information at hand, which outlines opinions on comprehensive sex education and concerns over the efficacy of abstinence in preventing pregnancies and STIs, an unlikely discussed reason would be abstinence as a means to achieve altered states of consciousness for supernatural experiences.