They absolutely care about us! I don't think everyone thinks non-Ancients are as worthless as ShB-era Emet. But... they ultimately see the animals as animals. It's sad when an animal doesn't meet its metrics and has to be destroyed, but it's just how it is. (They also seem to have planned to destroy Meteion - thus why Hermes grabs her and runs into Ktisis Hyperboreia, and says at one point that he needs to get the information out of her "before they're erased from existence" - but I'm not sure about that. Hythlodaeus and Emet don't object that no one wants to erase her. It is, however, possible they didn't think it would help. He didn't seem to be entirely rational at that point.) The entire structure of Elpis shows that they don't think living things have an inherent right to keep living. I think the "you have to meet your performance metrics to justify your continued life" thing also explains why people keep asking Venat when she plans on dying when you're in Elpis. She's done with her job. She's not meeting her metrics because she doesn't even have them any more.

Hermes was applying that logic to a group that it wasn't meant to be applied to - obviously no one ever intended for the Ancients to be required to justify their own existence to some external force on pain of death. But the logic itself didn't entirely come out of nowhere. If Hermes believes that the animals he works with are on the same level as his own people (which he seems to - I'm not saying it's rational or correct, but I think that's where he's coming from), then establishing performance metrics, a "supervisor" who can decide whether we've met those metrics (Meteion), and the usual consequences for failure (destruction of the entire species) is a logical extension. It's not a good one, but it does follow a chain of logic.