I think that slaughter of horses done in a humane way is a neccessary evil. I work in the horse industry, training horses and teaching riding lessons. Horses are livestock, but many people see them as pets, which is where the controversy comes in. I personally would not send my horses to slaughter. I have taken a skinny, blind, foundered old Welsh pony out of the hands of a kill buyer at an auction. I have taken in a starved, sick, horse and rehabbed him. I have adopted from a rescue. I would not allow my horses to have a fate, but I understand the need for the service for others.
It does cost a lot of money to get a horse euthed and then to pay for disposal. To many people it's just not an option. Many good, reputable breeders have gone out, due to the flooding of the horse market. Many auction houses have closed. It again costs money to haul a horse to auction, pay for the sellers fee, and then to only get $10 for your horse, it costs the seller money to do that.
I have seen sellers drug a horse and pass it off as a child safe mount. New owners get it home to discover it was drugged and now they have a dangerous animal on their hands. Is it worth risking the health of others to dump a horse? A boarder at the barn where I work at went to her friend's barn one August afternoon. She agreed to ride someone else's horse, a horse that was a dumped horse from a racetrack. The horse threw her, she landed chin first, yes, she was wearing a helmet, but as she hit her chin it did no good. She died 2 days later of severe head trauma. God speed, Nikki.
If this provides a way for a dangerous, or completely unsound horse to be a useful equine citizen and benefit others in some way, IE providing food, then so be it.
Rescues are completely flooded. I have heard stories from multiple people about people putting their unwanted horses in people's horse trailers at forest preserves, at auctions. Seen way to many starved horses. Farmers around here are converting their hay fields to crop fields, as they get more money that way. As a result, the price of hay is way up. The price of grain is way up. There will be more horses left out in the back pasture to eat what they can find and slowly suffer.
At least this gives the USDA a chance to do inspections of any horse plants. The industry will have to have the same standards as beef and pork plants.
There will never be a solution, or an end to the unwanted, unusable horses. Perhaps this will help some.