There is an inverse relation between the wage a job pays and the contribution to society that the job makes, with a few exceptions like doctors. The highest paying jobs are very often parasites on society. This seems to originate from the Calvinist work ethic where meaningful work is its own reward.
~ paraphrased from David Graeber, Bullshit Jobs
It's actually curdled milk. It uses an enzyme extracted from the stomach of a calf or a modern replacement.
Now buttermilk is more like rotten milk.