I'm pretty sure this is true homie.
Last I heard lactose tolerance is the "rare" one in a worldwide scope. At least to the level that westerners have it. Cows were plentiful in a few places, so a subset of humans developed a tolerance for lactose. Which, if I'm remembering right, was something that you grew out of after the breastmilk days were over.
Over time milk was available all over the place, but other areas are still way behind. That's part of what makes other countries foods so varied, the amount of dairy the average citizen can handle.