Can't hide headpiece of armor with connected head

There is some armor that does not allow you to use a headpiece. I know some people don't like this design, but I don't mind. What I do think is stupid is that we can't hide the helmet part.

Why would you design a feature that allows players to hide their headpiece and then subsequently design armor that doesn't allow players to use the feature? Clearly they realize players like to see their face, which is why they added the feature in the first place.