The Grand National is actually more Horse Friendly than it was many years ago. The number of runners is restricted, where it used to be a free for all with perhaps 40 horses running.
Jumps have been made more resilient and less likely to injure a horse that hits one.
Use of the whip is restricted and the whips themselves are lighter and very well padded; designed to startle the horse by 'cracking' as they are wielded rather than to cause pain. This last is controversial, I find (having googled this topic,) as the horse does feel something when they land, a horse's skin being extremely sensitive all over. But these whips are less likely to cut or bruise the horse, unlike the old designs.
Having said all this in extenuation I still dislike horse racing, whether flat racing or Nation Hunt, because it is an industry where horses are mere commodities. They are bred in their thousands and very few end up as successful race horses. Many of the surplus end up in pet food tins, or may be shipped abroad for human consumption.
Some may be sold to leisure riders and many of these suffer from ending up in the hands of inexperienced riders; the last thing a very sensitive, highly strung thoroughbred needs.
Because the horses are very immature when they start racing many of them suffer bad physical damage from the strain on immature bones and have to be out down. This is the aspect I dislike the most; those beautiful animals damaged and destroyed in the service of greed.
Added to all this, most punters have no interest in or love of, horses. They're just a living equivalent of a casino, a gambling opportunity. In all the other equestrian sports most of the competitors cherish their horses and spectators are knowledgeable and appreciative of the the skills and teamwork that a successful horse and rider combination show. (Which is not ignoring the fact that there are professionals in every discipline, some of whom may not have quite the same attitude to the horses they ride)