Every single blue BOFF I've ever recieved on my main char has been a female ferengi...all of them ugly.
I took me hours of cosmetic work in the character creator to make them passably attractive.
OTOH, they did come with some very nice abilities.
Curiously, my alt is a female joined trill. Every BOFF recieved, so far, has been a male vulcan. A girl just can't get a break!
They figured most of the subscribers would have 'augmented' female BOs filling the bridge of the U.S.S Harem, so the only way to make sure the male art assets actually got some use was to make most of the BO rewards male.
That way you'd at least see them in a window real quick while training Ensign Luscious.
My character is male, all my BO's are female. Why have it any other way?