What exactly is the wisdom behind allowing husbands to have intercourse with prepubescent girls?

The option of puberty (assuming it can be exercised even if the contract was completed by the father) can only apply when the girl has reached puberty. This means that if the parents were to send her to the husband, he'd be able to have intercourse with her because she's "able to endure it" although the actual process of physical maturation hasn't started yet, neither does she have any sexual desire for intercourse, nor does she understand what intercourse means. All that's required from her is to be plump and fleshy. What does the girl gain in this situation? This is the only time in my life where I feel like I almost completely disagree with a Fiqh ruling. This is way too convenient for the male, and in case she were to exercise her khyar-ul-bulugh at the onset of puberty, she'd have already lost her virginity against her own will. What is the reasoning behind this ruling supported by the most wise of the imams and sheykhs whom I greatly respect? JazakAllah in advance