>>10739562In ancient rome/greece and the muslim world today, little girls are for making families while little boys are for pleasure. This is because the boy is expendable. A boy impregnating three girls a day will produce 1000 offspring while the girl is pregnant only once. So if one boy survives, the tribe survives, but down to your last girl? You're fucked.
I think the sheer holiness of the coin slot was too high so roman/greek artists just wouldn't depict it at all (compare to not being allowed to depict various deities), but the penis was and is expendable which is why you see it everywhere. Even on japanese television where kids shows and Miyazaki moives featured them routinely.
Back to japanese media, if the anime has a thousand waifus it transmits happiness on a very basic level.