Don't you think that the fact that there are no consequences for their actions has a large bearing on the choices they make.
In a large part your post also reads as if kids have always been engaging in sex at the first opportunity. Yes I know a percentage do but that is not how your post reads.
All kids are going to have sex. At first opportunity. So let's not teach them discipline, just let them do whatever they want whenever. We will find a way to fix it so it does not present adverse consequences.
In large part that seems like teaching that there are no rules of any kind!!