>Because teenagers are genetically wired to want to bonk no matter what their parents say or teach.
>And bonk-minded teens aren't thinking of the consequences when the urge hits hard.
>I offer into evidence ... well, the world. Look around. Also, try and remember your own teen years.
Genetically wired, yes, but that doesn't tell the whole story. All the media is telling them that commitment-free sex is not only possible but desirable. Unlike real-life, media-entertainment thrives on conflict and drama. In real-life, that sort of thing destroys relationships. I've seen the macarena done at toddlers' parties. Look at the moves, hands out in invitation, a hug, pelvic thrusting, move on to the next partner. Listen to its words, "my boyfriend was out of town, so I cheated on him." Does it have an adverse influence on toddlers? No, but it does demonstrate a complete lack of thought on the adults' part with regard to the culture with which they surround their children. Look at the sitcoms - Happy Endings, Friends, Home & Away, whatever, everyone takes turns in sleeping with everyone else. There is the assumption that "boyfriend" or "girlfriend" or "going out" means "having sex" in pretty much any film where the subjects are 17 or older. Dancing has gone from telling a story like swan lake, or the rigid frame synchronisation and grace of the waltz or even the social mixing of a "country dance" to jiggling breasts and pelvis and spreading legs in a rather unsubtle simulation of sex, or at best, a "look at my primary/secondary genitals" display in a high-volume scenario which makes anything but visual communication impossible. And Society as portrayed in the media appears to be ok with this. Classical music is the domain of psychopaths, serial killers and the socially stunted.
Then we allow children to grow up with passive visual entertainment. For hours on end their prefrontal cortex which activates during critical thought and the exercise of love for another person goes dark and their emotional response centres are lit up, leading to the brain's pruning of unused areas affecting their critical-thinking capacity, while decision-making shifts to their over-developed emotional centres. Are we surprised when they make poor decisions about sex and fail to consider the long-term implications of their behaviour in general?
Don't have sex because of babies is a stupid KPI - of course it doesn't compute. Hormones and under-developed teenage critical thinking see to that. What is criminal is neglect of the moral principle of human worth. You don't refrain from sex because of babies - that's just a government policy problem - you do so because having sex exposes those involved to deep physical and emotional vulnerability to another person. For oxytocin -laden girls, the bonding is even stronger making the breaking of that bond later all the worse. What does your sex-partner think of you? Are they going to swap you out when their hormone level subsides or if they find you a bit irritating? If they aren't, get them to say so, in public. That's what marriage is. If they don't commit for life, they are holding out an option to ditch you. You deserve better. Don't let people treat you as if you're nothing but mammals. That's generally just short-hand for "I think you're here just to serve my pleasure."
As for my teenage years, I made it through without having sex. This isn't evidence of superiority, but it is evidence that teenage sex isn't inevitable. You can control it - but it helps if you don't let situations develop which promote sex. I'm not convinced even the Puritan practise of "bundling" is a good idea. You (and by that I mean the children) need to make a decisions about your social life and plan activities and situations. That means you (the parent) have teach children about their worth and where that comes from. Of course, if you think people really are "nothing but mammals" then a coherent and useful idea of human worth is a difficult one to develop and instil in your children.