This makes no sense on so many levels.
First of all, Christianity does not teach us that each human soul is of infinite worth. It teaches us that each human soul is of itself worthless.
All responsibility for how the animals are treated at slaughter cannot be put on the facility that does the work, though they obviously bear responsibility for much. If a facility is cruel, intentionally or unintentionally, then the customer also bears responsibility for buying the product.
It may well be that many abattoirs work on a model, that of the North American industrial food system, that makes it impossible to treat the animals properly, as well as having other serious stewardship issues. That does not mean that they should carry on and accept that, or that their customers should. If they cannot “afford” to operate properly, they shouldn’t operate at all. We don’t let them operate if they can’t afford to upgrade to whatever the health regulations are.
There are places in the world where the production of certain products has terrible effects on the workers - they spend their time being sprayed by pesticides as they pick fruit, or small children are forced to work long days in dangerous conditions. Would you suggest that if there was no other way to get these products, we should continue to support that way of producing them by buying them?
Meat is not something we need to have or we will die. It is, for much of the world, a luxury product. If you can’t find it produced in an ethical way, don’t eat it.
I think you have the teaching that ‘each and every human not worthy of salvation’ mixed up with the teaching that ‘each and every soul is of infinite worth’. Christianity teaches that no animal is worth more than a human. If fido and John were hanging over a bridge, to save fido would be a sin, it is a dog. To save John would be a good deed, even if fido dies. Yes, no human is worthy of salvation, but that does not mean that humans have no worth. Remember Christ died for US.
You are correct in saying that all responsibility should not just be placed on the facility. If the facility is being cruel for absolutely no reason then it should not be given any money from consumers.
It may be easy to say of these facilities, “If they cannot “afford” to operate properly, they shouldn’t operate at all.”, but you forget that people at these facilities have families they need to feed too. For them to simply stop running because they cannot afford a more humane way to kill animals would be irresponsible. Should the families of their employees starve just because Mary Moo Cow didn’t die just the right way?
Correct, some forms of production are terrible for workers, but i’m some workers would gladly do the job if it means that their loved ones wouldn’t have to starve, even those child workers. Istead of just shutting down these facilities we should work on better safety precausions, fairer wages, and more humane treatment of people.
And yes, meat is something we have to have or we would die. You could get your protein from beans and legumes, but only in part. Meat gives us all of the essential amino acids (ones our body cannot produce themselves) where beans or soy would only give you some of them. Soy itself contains too much estrogen, which is ok if you are a woman, but not as a man.
In short, it would be best if, instead of simply shutting down facilities that do not slaughter animals more humanely, we put pressure on them to do so, like by boycotting in mass or by only buying their meat products that you know were slaughtered humanely to send a message. But if, and i mean only if, for some reason these facilities cannot financially or legally change the way they do things, then to buy from them would be a venial sin if a sin at all, because through not fault of their own can they change things, and by
not buying from them you keep them in a state where they cannot change, ironically

.
Also, friends, please keep in mind that some of the ways animals are slaughtered today would have been considered very humane in the past. Which is why I say that you should not consider it wrong to buy forom a facility that cannot afford the latest and most humane methods of slaughter, as that definition changes overtime.