I feel most people think like that:
No talking openly about sex = being shy / narrow minded
Christianity had caused a millenia-lasting trauma on western civilization due to its views on sexuality as something sinful and necessary evil, and those views are unfortunately still part of our society to large extent. It will still take a few more generations to undo what has been done, if we keep the current course.
By no mean I do advocate for some extroverty discussion about everything with everybody, I don't get why people immediately get this knee-jerk reactions and think only in extremes, but some healthy middle ground would benefit us all. Actually I get it, it comes from our messed-up legacy from religions.
Discussion about healthy sex life, what it means to live good life, about death etc. should be definitely part of upbringing. There wouldn't be these clueless masses of teenagers/young adults most of us were part of sometime in our lives.
Just curious: What's your take on non-Christian cultures? They seem to have had a variety of views on the acceptability of homosexual sex, polygamy, age of consent, the line between endogamy and incest, acceptability of eunuchs/"third sexes", bride price v. dowery, etc. etc. but none of them really come close a modern Western sexual ethic of consent. Why not, in your view?
Take away any of those and it doesn't work.
I judge only society I live(d) in, which is western, and chilling effects of christianity-based teachings are all over the place, everywhere, in some form in everybody. Sexuality is still mostly tabu, although it doesn't make any sense since we all lose because of this. As somebody deeply within this society and surrounded by christianity, and in the same time outside of christianity since birth it is very obvious for me.
Its also not about bad-people-taken-good-words-and-twisted-them-in-the-past topic, which can be applied on many things in past and present.
Look how desperately unprepared teenagers are for sexual life. It takes a lot of time for many people to discover who they really are, what they want, need, can't stand etc. This is part of growing up, but society should help as much as it can, and I don't see this happening on scale appropriate to importance of this.
This can be part of much broader topic where I see our education systems (aka the process that should prepare us to be full active members of society) fail us to teach basic things - sexuality, communication, team work, understanding and developing yourself into best version of you possible, or even how freakin' taxes (or loans) work.
Equating having sex with what is a completely normal bodily function we have to do once a day was indeed a bad choice of words.
So according to your way of seeing things we should be openly talking about how we fuck, how I'd like to fuck you, how I got fucked by that guy the other day. No thank you. Keep it to yourself. There's no middle ground. What would the middle ground look like? I want to put my pee pee in your poo poo?
There is a healthy reason to find feces and defecation disgusting - feces carry diseases and are a waste product. Sexuality is not.
If we want to encourage more openly talking about sex, perhaps it's only fair that we also support people openly talking about what they find disgusting.
There is some healthy biological basis behind a disgust reaction to either, as genital contact carries diseases too, depending on how it's done and the history. In that regard, handling faeces is quite similar to close encounters with gentalia - either can be safer or unsafe depending how it's done, and both are a natural part of life which is healthy in moderation.
If everybody kept their sexual lives to themselves there would be no talk about what fetishes are degenerate simply because nobody would know what your fetishes are.