Because it should be as common as eating. The two biggest taboos in america: Death and sex. Yet, both are the most natural things ever. Both should be openly discussed.
The religious people try to control sex, as if its such an immoral thing. Its appears its their own projection onto everyone else, i.e., they have unclean and dirty feelings/thoughts that they try to suppress, thus attempting to inflict a similar morality onto others. Its all a crock.
In fact, part of early childhood development for children is sexual exploration of their genitals. You can do great harm to a child if you scold them for that, which I am sure religious parents do.
Religion does the opposite of everything that is normal and healthy.
That's debatable, below is an extract from the Roman Catholic Churches Catechism on chastity. Doesn't sound too abnormal and unhealthy to me.. but in today's hyper saturated world of lust it may be seen as 'abnormal' sure, but this wasn't always so..
http://www.vatican.va/archive/ccc_css/archive/catechism/p3s2c2a6.htm2351 Lust is disordered desire for or inordinate enjoyment of sexual pleasure. Sexual pleasure is morally disordered when sought for itself, isolated from its procreative and unitive purposes.
2352 By masturbation is to be understood the deliberate stimulation of the genital organs in order to derive sexual pleasure. "Both the Magisterium of the Church, in the course of a constant tradition, and the moral sense of the faithful have been in no doubt and have firmly maintained that masturbation is an intrinsically and gravely disordered action."138 "The deliberate use of the sexual faculty, for whatever reason, outside of marriage is essentially contrary to its purpose." For here sexual pleasure is sought outside of "the sexual relationship which is demanded by the moral order and in which the total meaning of mutual self-giving and human procreation in the context of true love is achieved."139
To form an equitable judgment about the subjects' moral responsibility and to guide pastoral action, one must take into account the affective immaturity, force of acquired habit, conditions of anxiety or other psychological or social factors that lessen, if not even reduce to a minimum, moral culpability.
2353 Fornication is carnal union between an unmarried man and an unmarried woman. It is gravely contrary to the dignity of persons and of human sexuality which is naturally ordered to the good of spouses and the generation and education of children. Moreover, it is a grave scandal when there is corruption of the young.
2354 Pornography consists in removing real or simulated sexual acts from the intimacy of the partners, in order to display them deliberately to third parties. It offends against chastity because it perverts the conjugal act, the intimate giving of spouses to each other. It does grave injury to the dignity of its participants (actors, vendors, the public), since each one becomes an object of base pleasure and illicit profit for others. It immerses all who are involved in the illusion of a fantasy world. It is a grave offense. Civil authorities should prevent the production and distribution of pornographic materials.