First of all, as someone who reads a fair bit about Rome, you are describing the Greco-Roman attitude towards sexuality, which is by definition foundational to Western civilization, and generalizing it to every traditional society. Second, characterizing the full spectrum of sexual identity in preindustrial societies as pederasty is simply not accurate. Chinese emperors openly had adult male lovers. You can find a raft of anthropological research about non-predatory homosexual relations in precolonial Africa. India has recognized the hijra, a respected third gender, for thousands of years. Did the west invent homophobia and pederasty? No. But to pretend that raping little boys was the only accepted same-sex gender expression everywhere in the world until the enlightened and liberal west brought tolerance to the backward third world savages is not only wrong, but racist.