By that yardstick, it would even be difficult to rationalize a preference of life over rocks. Yeah, we should embrace anthropocentrism and perhaps dedicate some care on not going too far with it.
Yes, taken to an extreme it means life is not preferable to rocks. But because I'm human, I prefer life to rocks.
But I think the point here is that we wouldn't be "doing good" necessarily by preventing a mass extinction; we would be definitely doing good to ourselves (no small thing) but for Earth's ecosystem? Debatable. Especially since we would possibly be preventing the spread of new species, since mass extinction events seem to have been so far useful tools in evolution's toolset.
