THAT is cruelty. That's why I wish I lived in the country so I could have a cow or goat or 2. Then my kids could have fresh milk daily (I rarely drink milk, but am not a vegan/vegetarian) and I would know it was from a happy, healthy cow. I grew up eating home grown meat, goat's milk, fresh eggs, etc. We knew the animals were as happy & healthy as we could make them during their lives. My brother & I neither one could drink cow's milk as babies/young children, so it was especially fortunate for us that my aunt had milk goats (milked by hand, twice a day I think) when we were young & so my parents didn't have to spend a fortune on alternative milk replacers (we are talking almost 40 yrs ago when these were not readily available).Our cows didn't get milked by us, they only produced milk for their calves. Completely natural. I don't see a problem with milking a cow who's feeding a calf, i.e. let the calf drink and milk what's left for household use, but we preferred not to. The cows didn't have a problem. Never had mastitis or any milk-related problems.
What I find cruel is farmers who take away day-old calves, refusing them their mother's milk. And those poor cows at the dairy farms who has to mass produce milk. Their udders end up rubbing against their legs until they got sores. I've seen cows that had to be propped up at milking time, they could barely stand or walk.