I would say the researcher failed to take into consideration the ancient Greek and Roman empires where gay men were a normal part of society. Even married men openly had gay lovers, some barely into puberty themselves. Notice the civilizations they built. Even in the early days of the church, it was not unusual for a Pope to be gay. One or two were actually gay lovers of the previous pontiff.
So I don't think that's why the gay bashing started, but more to ensure a larger population.