Krauze is confused. How could scientists think the extermination of the human race over the course of a few decades would be bad, bad, bad, while thinking that the gradual extinction of the species over the course of millions of years would be inevitable and of no great concern.
It’s the same reason that we think murder is a moral wrong, but having a heart attack or dying of cancer is not. Or rather, the reason we treat a 90 year-old dying of lung cancer as a sad part of existence, while we see a 30 year-old dying of lung cancer and think evil thoughts about tobacco companies.
Species go extinct, just as people die. It’s a fact of life. There was a time before humans, and there will be a time after our species. There was a time before I lived, and there will be a time after. I don’t get into a moral huff about that. No one is advocating the forcible extinction of the species, merely posing the reasonable prediction that humanity will, at some point over the next several million years, not exist.
As happens so often in contemplating mortality, the question becomes “What shall be my legacy?” A planet despoiled is one legacy, and we can make choices which which leave the planet far worse off than it was when we found it. And we can make other choices. There are even some who think we ought to.