The only qualified line-drawer I know is Jesus Christ.  Jesus never discriminated against anyone.  He also never ordained any priests.  The organizational church (which has created the celibate, male-only priesthood) is patriarchal, sexist, and needs to be changed.  It is injustice, pure and simple, to deprive more than half God's children of one of the Seven Sacraments.  "Either ordain women or stop baptizing them".