I would recommend reporting this as a bug to Larian if you haven't already - there's a Report a Bug link up along the top of the launcher.
It is not a bug - it's a personal preference - besides that it is only a
"nice to have" feature and should therefore be very far down on Larian's list of bug fixes and features to to implement. If it were to be implemented the option "Show/Hide Head Gear" should probably be in the "Gameplay" settings section (ESC menu).
