Neglect is abuse; slaughterhouses are not.
I didn’t say they were. There needs to be some facilities for taking properly taking care of sick, injured, or too old horses. Like any animal, sometimes putting them down is a necessity. You have to be able to do something with the carcass. You can’t just let it rot.
It’s blaming the abuse and neglect of animals on lack of slaughter houses that’s wrong. That’s solely the responsibility of the owner.