IMHO and from what I've heard before, Father in this case means the same as Master and we're to call no man MASTER because God alone is Master. I don't know what the original language is but perhaps someone smarter than I will let us know.
23:8
But be not ye called Rabbi: for one is your Master, even Christ; and all ye are brethren.
23:9 And call no man your father upon the earth: for one is your Father, which is in heaven.
23:10 Neither be ye called masters: for one is your Master, even Christ.
23:11 But he that is greatest among you shall be your servant
So if one were the greatest among us I doubt he would have fancy titles, robes and hats