Why is there a stigma to talking about TTC?

Why is TTC such a secret thing and why does society act like we can't talk about it? I feel like I can't even talk openly about it my sister or she gets awkward. I understand people have fertility issues, but infertility seems to be so common these days. Why can't we be more open with people we actually know? I feel like it would bring people together. So many people battle with TTC but never talk about it with family or friends. I just wish there wasnt such a stigma behind it. Why not be open so that people can get love and support? We all have sex, it's not like people don't know where babies come from. It just boggles my mind. Of course don't talk about it on social media if you don't want, but why does it have to be so private that family or sisters don't want to know? 😧 I just don't see where the big deal is. Obviously privacy is important and between a couple but still, why is it such a taboo to talk about openly If you want?