It promotes monogamy, self-control, love, commitment. This is destructive for women who are not young, physically attractive, economically well-off. Capacity for love is a virtue. We must form correct habits, to channel sexual desire to promote the capacity for love rather than stunt it. Traditional sexual morality develops the right habits for sexual virtue.
Sexual maturity involves incorporating sexual desire into one's personality.
It may manifest itself as chastity, fidelity, or passionate desire, depending on circumstances. Giving in to certain desires makes one less capable of loving. That is a grave harm.