I wouldn't say that all women are crazy. But I would say all women are very emotional and hence often not logical. Also--and more importantly--that men and women have different sexual needs.
Here's how I see it: For the species not to die out it must reproduce, hence men and women have some "hard wired" desires.
Men must we willing to copulate whenever the opportunity presents itself. Just imagine what would happen to the species if men were only fertile--or interested in copulating--a few days per month. Men and woman's reproductive cycles would seldom match and the species would die out. So "mother nature" designed men to be horny all the time.
Women only need to reproduce a few times in their lives for the species to continue. What's important for women is to find a mate that will take care of them and their off spring--meaning feed, clothe, protect, etc. "Mother nature" makes women horny in the courtship phase of relationships, the time when a woman is trying to attract a mate. Once she has a mate she only needs to reproduce a few times in her life for the species to continue. Too many pregnancies can harm a woman's health in addition to the problems of feeding/nurturing too many off spring so women lose much of their sex drive when they're in a stable relationship--especially when they need to devote time to caring for their off spring. Women being horny all the time is counterproductive for the species. If women were horny all the time they'd have multiple partners and would not be able to maintain the type of on-going relationship needed to feed, clothe, and protect children until they're old enough to care for themselves.
It's just my theory. But, to me at least, it explains well the difference in sexual appetites between men and women.