The problem here is really finding a way to reconcile sex education with people's morals. If someone is against sex before marriage (for religious or other reasons) then you can't get behind any education that deals with sex outside of that framework because of the implicit condoning of the behavior.

It would be like someone saying they're against crack cocaine, but then telling you how to source the drug and consume it "safely" if you do decide to do the drug. Of course even in this example someone knowing how to do this "safely" is better off than someone without any knowledge at all, but you have to live with the fact that you may have pushed some people in the direction of doing something you find immoral and that's not something a lot of people will want to do.

It's been many years since I've been in high school, and to be honest I don't even remember what we covered when it came to the topic but I'd be interested if there was some sort of middle ground here that could help improve outcomes.

For example, one could "promote" abstinence until marriage, but then discuss how one would deal with birth control in that context, and how one might deal with the spread of STDs that a partner may have contracted outside of overt sexual encounters?

I'm thinking something along this lines could serve as a useful middle ground and later on pave the way for when more liberal attitudes towards sex become the norm.