What I had in mind were the people who volunteered for experimental medical procedures. Transplants, blood transfusions, neurosurgery, skin grafts, etc. The techniques were only perfected through the suffering and death of a vast number of nameless people.
> Animal testing is weighed against what benefits us in even the slightest way and is some sort of "unnecessarily cruel" metric.
> We say these things are okay, and important, but when I think that almost 13,000 animals were killed, beagles, cats, monkeys, rats, just so we could have splenda, I think that whatever we value non-human life at must be so trivially small.
That is a deeply philosophical argument. We can obviously agree that -- all things being equal -- a human's life is worth more than an animal's life. But exactly how much more valuable is it? Can we accurately quantify how many mice can die so one human can live? Does it depend on the animal and its intelligence, at least as we perceive it? The questions can go on and on with no end in sight.
Now, I'm honestly not intimately familiar with what goes in the life sciences, particularly when it comes to experimenting on live subjects. Nonetheless, I am convinced that modern ethical standards are a good way to set universal limits to what can be done to animals in a laboratory setting, while also ensuring that we as humans benefit from the results. The alternatives would be either to delay the discovery of new procedures because we don't want to hurt animals, or to just experiment on humans directly. Neither of these sounds like a better option to me.