This is anecdotal but pretty much all of the lactose intolerant people I know love dairy more than the lactose tolerant people. Something as small as your body not processing milk isn't enough to stop them
Humans:
Let's breed all these pants together to maximize production of the chemical, invent a rating system to determine which ones have the most, then hold competitions to see who can tolerate the highest levels.
Completely spitballing here based on your anecdotal observation, but I know that with lactose-intolerance, you're lacking lactase for processing the lactose, so the lactose makes it unprocessed into the gut, where the gut microbiota then process the lactose and cause the usual symptomes.
Well, and those gut microbiota can signal to your brain that they want more of a given food (source).
So, maybe those bacteria in your gut fucking love lactose, because it is basically sugar, and so they instruct you to self-destruct.
They had a gourmet cheese tasting in a luxury hotel in Beijing some years ago; it was treated with the same kind of combination of curiosity, wonder and mild horror that the west would regard, say, fermented shark or sheep’s eyeballs with.
As a Western European, I can verify this. I will fight you for cheese. Doesn't matter if it's blue stilton, sharp cheddar, chevre, feta, or maasdam. Cheese is life.
Btw, there's a batch of people on the westcoast of africa who developed lactose tolerance indepently. Seems it happens all the time, if a community relies heavily on livestock.