No one's answered my question as to why they're so resistant to giving the name a gender neutral one...
Well, I didn't want to answer honestly but.. you sound like you are asking without wanting to troll....
Because the only gender issue with the word is the one *you* have with it. If anything you need to stop seeing sexism in words, because I assure you, nobody else reading Man-At-Arms thinks that's only males... that's just you.
You have to understand this, to us the word includes females because it describes non gender specific skills of a medieval troop type. Just like soldiers and warriors can be females too... in our minds there is no separation between female and male in these terms. That is YOU making this separation.
This is also pretty much why I never take these topics seriously

And aside, Man-At-Arms is historical. It gives D:OS some flair.