Ujl,
semen is oblated into fire , female body, through vagina, not sacrificed into fire of vagina.

see, women body is the fire.

But in the case of male, "organ" is the fuel; body is not the fuel. Even when body changes with age, organ might stay same (stiff), hence fueling fire.

but in women, As they grow old, the fire (which is their body) turns into just heat.

i am not trying to make any point, i am just observing how your topic answers, one of the many reasons, why men and women are that way.