as if the topic is taboo or something
I guess in a way, it is still considered taboo. If it isn't, then we will have couples having sex wherever they want, or a guy will just whip out his schlong and fap when he sees a sexy lady. The laws against indecent exposure and related to it, also support the idea. It seems anything related to the reproductive organs are still a little taboo. Apart from sex or masturbation, people will be uncomfortable talking about the size of their package or boobs. They don't usually share if they're shaved or trimmed or bushy down there. Even just getting an obvious hard on outside elicits different reactions from people.
You mean this doesn't happen in your location already? Lol
It's an interesting topic I guess and depending where in the world it's discussed those discussions will take into account the cultural situation.