Of course this is just my opinion and I can't stand Mattis because I also thought he was okay until he challenged POTUS, but I have to disagree with your assessment of single guys.  I know some guys that never wanted to settle down, so they never married, still acting like they are in their 20s banging a different girl every weekend and when they get into a relationship its very short lived.  Other single guys get married to their careers and wont let anything else get in the way of their success going up the corporate ladder, while others never find the right girl.   Then one day they retire and realize that there is something missing in their lives like grand kids but its too late and will continue to live a life of regret.  This can happen to anyone working in a government job, small business or the military. Would we also say the same thing of single women? Its all about the choices that people make in their lives and they have to live with those consequences for the rest of their lives.