I thought it was self-evident. Killing someone innocent for the good of others is never acceptable; people are ends in themselves. This is a general precept in most ethical systems with the notable exception of Millian Utilitarianism. To be clear, I am not making an argument against justifiable self-defense, as that is almost always accepted as a different kind of situation.

Example: we allow people to be killed for the good of others as long as their death allows the survival of more people. This is the poster's argument distilled. As such, it would be morally justifiable to kill random people for their organs, as one person contains enough organs to keep dozens of people from dying. If you need a liver, and your neighbor needs a spleen, then there would be nothing wrong about abducting the first person you see, butchering them, and taking what you need.

This argument is essentially that we should allow people to be killed, harmed, maimed because the number of people it help would outnumber the number of people harmed. They are the same argument. They both treat people as means rather than ends.

There are many nations in the world where you can be brutally killed for being gay, or any number of other things which shows up in medical records. If we include imprisonment, the number rises. The cost isn't just "some people might get embarrassed". It's a lot more like "hundreds of thousands of people will be brutally murdered by others or their state".