A common reason to deny women the Priesthood is the old adage "Women have Motherhood and Men have the Priesthood." This correlation is false. Fatherhood is the equivalent of Motherhood, not Priesthood.
Motherhood does not require one to be "worthy"--there are bad folks who become mothers and there are good folks who cannot.
Fatherhood does not preclude one from being a Priesthood holder, in fact, more often than not fatherhood enhances his rank in The Church.
A woman cannot asexually reproduce, so even if using donor sperm, sperm was still necessary, men can unilaterally exercise the Priesthood. Since 12 yr olds receive the Priesthood one is never in need of a woman to exercise it.
There are a great many reasons why Motherhood and Priesthood are not equivalent, yet no matter how many times the theory is debunked it is still used over and over. Why is that? Why do thinking people not understand that the correlation falls apart instantly? Let us be the voice of reason and ever push forward spreading the word that the two are not equal and never will be.