My grandfather worked with horses all his life. He was a stablehand in the Camden underground stables before WWI, lied about his age to join up and then looked after what could be termed the Warhorses. After surviving (barely, but at least the Germans dug him out from underneath bits of horse, stuck a metal plate in his head and then fed and clothed him until he was freed from a POW camp shortly after Armistice Day), he continued to work with horses.
He had a story of how he and the other stable hands thrashed a drunk jockey for being cruel to the horses (now about 100 years ago) and the boss just decided to studiously ignore the summary justice. They loved the horses and did all they could to keep them safe, well and happy.
He wasn't a fan of the National because of how dangerous it was for the horses - he felt that it was too much of a risk for them. And he clearly despised the use of whips in the way they were used for racing. He also detested hunting, as that was a meaningless activity based upon cruelty when, as he put it 'a shotgun's more use than a red jacket if you're trying to keep foxes out of the chickens'. Hunting Otters made him incandescent with fury, coursing was 'a bloody pointless activity when you could use those dogs to catch a couple of rabbits for dinner' and he never quite forgave my grandmother for buying fur coats following a legacy as they were 'for vanity, not warmth' and used to refer to her coats as 'those poor bloody dead things in your wardrobe'.
However, what he also said was that some horses need to race. They love it. You can see the ones who love it beforehand - their ears are up, the energy is obvious; they're excited, they're happy, they know what's coming and they can't wait to do it. And whilst some love the flat, some love going over sticks.
For him, the issue was the money and who he called the Bastards. They were the ones who didn't care if horses were injured as long as they won. They were the ones who made the jumps too big because the punters wanted it to be more exciting and would pay to see horses taking greater risks, not really caring about the deaths other than if they meant the loss of a stake. They were the ones who didn't really give a shit about horses or racing but wanted to go to dress up (presumably in their poor bloody dead things), eat fancy food and never actually look anywhere near the course.
I think he'd approve of the way pressure has been applied to make jumps safer and the changes in animal welfare legislation - but he'd also say that it still isn't enough - the money involved ensures that it isn't enough, but whilst people are prepared to bet more than they have on a particular colour of silk, there will still be too many life ending injuries.
He didn't want racing to end altogether, though - he'd already witnessed the near extinction of heavy horse breeds due to their not being needed anymore and horses were his life and love; the world would be a lesser place without them. He'd have nothing but contempt for people who would say 'so what?' or 'good, they shouldn't have existed in the first place' or 'well, they might die in pain so it's better that they never existed'.
But then again, people who have actually witnessed death on a battlefield tend to feel differently about things compared to those who have never known anything more than a little discomfort and existential angst from a position of absolute affluence.