You probably have a point, although I would argue that kids should be just as uncomfortable talking about sex with any adult, and that discomfort probably exists for good evolutionary reasons.

Parents should still be the ones who decide when these conversations are appropriate, and how they should take place.

Even if you argue that the idea of "sex ed" in schools for adolescents is in principle a good idea, and I can see where you're coming from, in practice we know that if you give these institutions an inch, they'll take a mile.

The most practical solution as far as I can see is to just implement a zero-tolerance policy on teachers talking about sex to their students.