@Clive K 100%
Cruel training methods are usually down to ignorance or economics, or a mixture of both.
Ignorance - a lack of understanding of the instincts, needs and psychology of the animal and belief that a standardised training regime works with all animals.
Economics - it takes far less time, and therefore costs far less, to batter an animal into submission than to encourage it to work with us.
We have a border wallie on our farm, he's a rescue. He is extremely well-bred and has an incredibly strong working instinct and is desperate to please, but his previous owners (a nice farming couple who had no understanding of him at all) simply stuck him in a kennel and spent little or no time with him. They tried to teach him to work sheep but it didn't work, and they eventually sent him away to a sheepdog trainer. He came back from there terrified of sheep, and panicked if they tried to fit a collar and lead. He was also frightened of all men, although he was fine with women.
And, although he was very happy to chase squirrels and rats, he had no interest in chasing a ball.
Pure guesswork, but the indications are that the "trainer" tied him to an experienced dog, which dragged him around chasing sheep, which does work with some dogs but not with others.
A year later and he's a completely different dog, he loves working sheep and is leading a very happy life. He's great. Just two problems remain, and I just can't be bothered to deal with those problems because doing so will cause him stress. He wears a harness because he's fine with a harness and the harness is a good replacement for a collar, and he simply won't go into the house, he has never been inside a house, but that's fine, he has a large kennel and he doesn't need to go indoors. He is however very happy to travel in cars, vans and tractors.
I understand and love dogs. A lifetime ago I competed at championship level in dog obedience, and later I moved to training problem dogs. I don't understand horses at all, but have been told by experts that their training needs are almost identical, my problem is that I can read dog body language very well but can't read horse body language at all, so I can't form a bond with them. The main difference between dogs and horses seems to be that, with a horse, we just need to show it what we want and it then remembers it, but most dogs need far more repetition. Apparently most stallions are similar to dogs in that respect, but stallions are fairly uncommon.