Reason we don't have the missing genders is they said they didn't have enough time to make both races and they wanted to do hrothgar but knew people wanted viera, it was said in some past statement.

I'm assuming that's probably why we have the headgear situation to,rushed time and couldn't get the right fit in time, my personal opinion would be I wished they'd done the hrothgar both genders then in a future expansion done viera race.