Why are sexual discussions so challenging for humans?

Has anyone else noticed that general discussions of sex seem to frequently trigger a lot of anger, judgment, and discomfort among people? I'm not referring to sexual abuse. That is of course wrong, a crime, traumatizing, and painful to discuss. I'm just referring to discussing ideas about sex with consenting adults. Or when someone has a sexual problem and they'd like support and advice but they receive criticism or get shut down instead. I've had several friends tell me that I'm the only one they can openly chat with about sex for fear of judgment/shaming from others. Sometimes even sexual issues which don't appear particularly controversial seem to really trigger a lot of anger and arguing. In my view, human sexuality exists along a continuum. I don't perceive it as black-and-white. Again, I am not referring to coercion or assault. I've noticed that a recurring problem in adult relationships is when one partner does not understand the other's sexuality...so they feel they have to control it or change it somehow...which leads to more problems.

What do other people think? I'd be interested to read any responses which are calm and open-minded