The demand for child sex is fueled by porn & fornication which in turn comes from decoupling sex from procreation, marriage, and family.
Ultimately, this has its source in idolatry and the rejection of God.
We're being shown in real-time the logical progression of liberalism. Rejection of Jesus -> Rejection of external divine authority and law -> acceptance of internal authority and do whatever I want -> acceptance of birth control -> sex is for fun -> acceptance of divorce -> acceptance of baby murder -> acceptance of child sex etc. etc. etc.
The proper end of sex is procreation.
The proper end of eating is nutrition.
Both have pleasure associated with it, but it is not the proper end. The purpose of pleasure is so that you have sex, so that you eat, because procreation and nutrition are so important to life.
If you say the proper end of sex is pleasure, then what follows is hedonism, fornication, rape, pederasty and other evils.
If you say the proper end of food is pleasure, then you get obesity and disease.