I don't really like these insults

This is not a polite way to converse QT. You're clearly talking irrationally.

People do cover their mouths, there are masks.

Covering the eyes is sometimes done with goggles. In cases where people cry they tend to blot the tears with something. It's something required for sensing the environment (site) whereas nipples don't do much to sense the environment. There is no nipple literacy and hand-nipple coordination isn't that useful.

Sometimes ears are covered with hats or muffs. As I stated though, I don't advocate covering them, because they aren't at the same risk level as nipples.

So stop misrepresenting my arguments, if you can only win with straw men then you're a loser.