Sex is completely divorced from its cultural and moral historical framework and treated as nothing but a biological phenomenon and physical health issue.
Well, clearly, there is more to it than just the pure biology. But this is true of anything I can think of.
The eye and the stomach have larger cultural and moral issues attached to them (some images are forbidden to look at, certain foods should not be eaten, etc.). Imagine a school where children are not taught how the stomach processes and breaks down food for fear that children might eat pork. Or eat during the Holy Fasting Time. Or, I suppose, to keep the analogy more intact, for fear that they might eat something poisonous. This is ludicrious.
All the descriptions of the problem and solutions to it from your side of the cultural divide have this pragmatic biological focus that to someone on the other side of the divide appears dehumanizing and culturally suicidal.
I don't understand what's dehumanizing.
Some aspects of the sexual act can be easily broken down into biological components. Other aspects can not. Same goes for eyesight, stomachs, cancer, etc. The aspects that cannot be broken down this way fall into subjective areas that are harder to teach but no less important. That's why I think kids should also be taught poetry.