There are many who make pets of animals. Of course, loyalty to a trusted pet or pack animal goes far and I wouldn't expect a loyal and trusted lifelong friend to be killed and eaten - I'd be very suspicious of the person who did.
But if we are going to raise horses specifically for eating, then what's the issue? The Koreans (and ancient Aztecs) like dog. The Chinese like cat. Many Brazilian and Australian aborigines eat parrot. Many Africans eat monkey. So why are horses not treated like cattle here? Or right here, right now; they used to be eaten much more commonly in the west during colonial times.
Me, I just draw the line at cannibalism. And Spam.
We aren't doing that. We are talking about disposal of undesirable mustangs, that are the result of many many years of putting off the problem by BLM.
No one raises horses for slaughter here on any kind of scale. They are too long to grow to mature weight, and more expensive to feed and care for than the few hundred dollars you get for their meat. Even unregistered and mediocre horses are worth more as a riding horse than for slaughter.
There are a few classes of animals here that end up in slaughter.... The broken down old ones, the unruly or ruined attitude horses, The ones someone dumps in a hurry for a few dollars, and the premarin foals, who are another kind of waste altogether.