Also, I don't see it justify that targeting corporations works?
Is it more effective to convert high-profile individuals in animal slaughter-related corporations, to pass regulations for these corporations, to become experts working to create welfare standards from within, or what? It doesn't tell me much about where to orient my animal welfare charity towards.

That's not an information the doctors have at hand when they're trying to figure out who should receive oxygen.
(Also, it doesn't matter what's the utilitarian way to say, what matters is saying correct things - and utilitarianism happens to sometimes help with that.)