A historian is a person who studies and writes about the past and is (regarded as) an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all history in time.
So, since you were not there "back then", you are being told what history is by historians. One of the greatest and accurate historical account of the universe is the bible. (Insert hearty laugh here.)
But why the disparity between homopedophilia and heteropedophilia? Fun with a dick has no direct consequences. You can do it yourself or have somebody do it for you. Unless, of course, you put it into something "dirty" (biologically speaking.) Plus, males were owners of the universe and females were property. (Probably still that way in a lot of places.) Fun inside a girl has some pretty drastic biological consequences if not very careful. And who, back then, was careful? There's chlamydia, gonorrhea, syphilis, genital warts, herpes, chancroid, hepatitis A, hepatitis B,and hepatitis C, trichomoniasis, pubic lice ("crabs"), and most recently, HIV. The other "serious" biological concern usually takes 9 months to resolve.
A dad (male, of course) hears that his son has been expelled from school because he was caught with his (female) teacher in flagrante delicto. Dad smiles as he chastises his son, then takes him out for a Happy Meal.
A dad (still male) hears that his son has been expelled from school because he was caught with his (male) teacher in flagrante delicto. Dad frowns (because he's not gay) as he chastises his son, but (in today's society) checks to see that it was consensual and then takes him out for a Happy Meal.
A dad (male, and proud of it) hears that his daughter has been expelled from school because She was caught with Her (male) teacher in flagrante delicto. Dad explodes in rage and demands that Her teacher is tortured for months and then executed twice. Why? He thinks that his daughter was injured (whether or not She was, is irrelevant to him.)
A dad (male but soon to become very confused) hears that his daughter has been expelled from school because She was caught with Her (female) teacher in flagrante delicto. Dad frowns (because he's not gay) as he chastises his daughter, but (in today's society) checks to see that it was consensual and then takes Her out for a Happy Meal. (Females don't have penises. Fingers do not inject DNA ladened semen.) He does wonder, however, if he has any chance with the both of them as a threesome.
The idea of rape was originally due to the "property" concept a man had over a female (of any age.) Virgins, back then, were worth more than a thousand goats and horses. Take that "value" away from one of his females, and the "owner" is going to get really pissed off.