They also just straight up ignored the fact the majority of humans never adapted to milk. It's something like 70% of the species that has lactose malabsorption lol
I'm not sure but I do think that evolution played a big role here. Probably not for the reasons in the OP, but because it's a way to convert grass into portable food with decent long-term storage (cheese). This is huge for migratory populations, but still helpful for sedentary ones due to winter.