My friend would spend summers at the family farm, and the youngest kids would be issued a rabbit as a pet for the duration. They'd then make the kids watch the rabbits be slaughtered and cleaned, and serve them up at the end of the vacation...
Straight psychopath approach to child raising. The adults were all convinced this is how you made kids grow up tough
That's straight from the TV trope book, this is how movies/shows portray Evil Organization training ruthless spy assassins (except usually it's a dog, and they have to kill it themselves).
Most tropes have some basis in reality. I've met a few farm-owning parents who view any kind of sentimentality towards animals as counterproductive.
But that's normal - emotionally boding with a farm animal you intend to slaughter and eat is indeed counterproductive.
The trope is about something different - it's about intentionally making a subject bond with an animal over long time, as with a close friend, and then finally making them kill the animal as a final test of loyalty.
Doing that in real life, and for no good reason, is just sick.
It is, those people think this practice will speed up process of that bond being understood as counterproductive.