I think it is because in our society sex is thought of as something not to be discussed outside of the closed doors. That is not the way that I feel. Sex is something to be enjoyed by both partners and discussed, others may know somethings that you do not.
To be politically correct it has never been okay to discuss sex in the public forum. Sex has always been discussed in private and between two concenting adults. Reason for this is so that no one will be labeled some type of sexual pervert or worst, offender. Good luck
Or they wish they were...lol
Its all an act, really, they are freaks in the bedroom.
Because people on the internet who mention sex aren't doing so out of intellectual curiosity. The next question will most likely be, "What are you wearing?"
Because some were taught to not talk to strangers about such things. And others just don't get it.