I'll just address two points:
(1) The concept of an age of consent, based on the age of reason, dates to an era centuries before the sexual revolution. At that time any sort of sex outside of marriage was punishable by law, and while the law was not always enforced - particularly among the lower classes - in theory sex outside of marriage (a.k.a. extramarital sex or fornication) could even be punished by death.
Well obviously no one wanted to execute a six year old for fooling around, so they created an age of consent based on the idea that persons under that age did not possess enough reason to understand that what they were doing was wrong, and therefore the courts would not be allowed to punish them. The age of consent, therefore, was established to create an immunity from the law for children. This is why the age was so low - typically ranging from seven to twelve depending on the jurisdiction. It wasn't that they thought that persons above this age should be having sex, it was that they thought it appropriate to PUNISH someone seven years old, ten years old, or twelve years old (depending on the jurisdiction) if they voluntarily engaged in sexual intercourse. The idea of statutory rape was introduced so that, if someone under the age of consent engaged in sexual intercourse with someone above the age of consent, the entire responsibility for the crime was placed on the older party.
(2) College girls are actually LESS susceptible to being raped than girls who do not go to college. Feminists are just lying about a rape epidemic on college campuses.