Just like a fire is part of a forest's ecosystem it's possible that a mass extinction is part of the Earth's natural lifecycle and is beneficial in the very very long term
Are we happy, however, with anything that's beneficial to Earth's long term natural cycle if it happens to come with our own potential / likely extinction? (or at least a very heavy hit to the lifestyle to which we've become accustomed).
I care about the environment insomuch as it's upon what our very lives depend as opposed to the environment in and of itself. It's my enjoyment of the environment and the wonder of its variation that is something valuable to lose, but it's loss is also an existential threat to, basically, me and all those I care about in the universe.
Life on Earth probably has one (~maybe two) very very long terms left before Sun vapes it all. Also, since all under-your-feet fossils and minerals are basically depleted, the chance for another technological civilization after ours is vanishingly small.
I don't really care about the other later phases of Earth's natural lifecycle - I kinda like this one. So much so, that I'm going to be investing in the other ones at all.
Now if only that was the kind of short term thinking humans were afflicted with.