'The most common cause of sexual sin is isolation and loneliness. The sexual appetite is an urge to overcome isolation, to give and receive another person. A person who is fulfilled in their daily life through other forms of “knowing and being known” will find that chastity frees them to be generous and loving and to receive love and generosity without the clinging neediness of sex. The problem is that most people in the contemporary world are literally starving for human communion, and sex fills that need at least temporarily.
Negative chastity, the kind of chastity that limits itself to saying “Thou shalt not,” has consistently failed to persuade the postmodern world because it is madness. The vast majority of people will eat things that are designated “unclean” by their religion or “unhealthy” by their doctors when faced with starvation. In most cases it's not even voluntary. Unless you have strengthened your will to a superhuman extent it's not possible to starve yourself to death. Likewise, unless you've devoted a huge number of character points to picking up the “Stoic” superpower you will simply not be able to endure the kind of social starvation that negative chastity demands in the contemporary world. The way that we live, our architecture, our social structures, our institutions, are all far too individualistic for it to even be possible. From the new institution of “the single life” to the catastrophic experiment of the “nuclear family” we have created a culture of isolation. In order to gain increased autonomy for the individual citizen and the individual family we have severed the ties that hold communities together. Within this insular existence sex is a powerful means of escape. Telling people that they can't have it is like telling a child who has eaten nothing in days that she shouldn't eat a lollipop because it's bad for her teeth. The distant threat of cavities will simply sound hollow and meaningless compared with the present experience of hunger pangs.'
Melinda Selmys, 'Sad Bad Sex' at: http://sexualauthenticity.blogspot.co.uk/2013/04/sad-bad-sex.html