Monfang, it's not an argument you are going to win.  The rational will always be that they are not there.  No matter how great a storyline is made to justify their existence, no matter how plausible a story or background is made to fit a female Space Marine chapter into existence people will say they do not exist.  Games Workshop crafted a storyline that has no true canon...except Space Marines can't be girls.  In my particular game I had to accept.  If ever someone runs a female Space Marine game, then they will automatically be running the risk of losing player interest and recruitment.  But that is the way of the fantasy universe.<br/><br/>To me its simply the reaction people have to the notion of female Space Marines.  There is a visceral feeling of nerd rage that comes across which seems...very much out of proportion to the subject matter.