If all sex is, as taught in schools since it was introduced, is the "scientific mechanisms" ie; this body part produces this function for this purpose, then sex can be divorced from all morality which is where we find it now.

I sort of disagree with you here. When you start from the realities of biology you tend to end up at normal sexual mores. As an example, if you only have sex with one person who you know doesn't have any STDs, you don't have to worry about STDs. I find that nowadays people are overly cautious when it comes to safe sexual behaviors or overly libertine when it comes to risky sexual behaviors. You don't need to wear a condom if you're in a monogamous relationship. You really shouldn't have sex with other men if you're a man, but we can't say that because it would hurt people's feelings.

At any rate, these people want things both ways. They want to say that their education is based in science and not morality, but they are deathly afraid of offending homosexuals, trannies, etc. I was lucky enough to more or less figure this stuff out on my own but many teenagers are not.