Because there is a HUGE double standard in this world. Unfortunately, it is the woman that has to carry the baby and usually is the one with the custody if the pregnancy was unplanned and the boyfriend ditched her.  It is a shame and I feel sorry for any woman in that situation and curse the bastard that left her!  Society looks at the woman as loose and the man as virile, which makes no sense to me as they both are doing wrong by the child.