"Made for humans" also draws attention to the fact that the milk you're drinking from a cow is not being drank by the offspring of that cow like it normally would and many people don't realise you have to keep making diary cows give birth to get more milk. Newly born male cows are usually turned into veal in a few weeks and female cows are separated from their mothers so they don't drink the valuable milk. Milk givin…
I hosted a meetup on “dairy tech”. Before the presentation, I think I had an implicit assumption that cattle raised for beef were treated poorly. I came away realizing that cattle used for milk production suffer more. In the most efficient dairies, they never leave their enclosure, are kept pregnant continuously via artificial insemination, and are injected with hormones.
I think you could certainly argue that. Beef cows are slaughtered at around 3 years and diary cows are slaughtered at around 5 years but after giving birth with their offspring taken away several times (both have about a 20 year life span).
Personally, I don't understand how vegetarians justify it as being much different in terms of animal cruelty. You're still paying into a system that's killing animals for your benefit.