The subtext of this desire to depopulate the planet (and a 80% cull is nothing less) is that humanity is a uniquely dangerous and unnatural intrusion into the natural world. We have been here for 100,000 years and the world has survived just fine. Modern industrial civilization has caused some harm, but nothing compared with the last ice age, which destroyed the ecosystems of Europe and North America and reduced the tropical rain forests to savannah and fragments. Nothing we have done or will do compares to that. Even the great stress that fossil fuel based humanity has created will only last another 100 years or so, then we will move to more durable power sources. Already, the richest parts of the world are healing their environments, and forests are expanding in North America and Europe to extents not seen in centuries. The same will happen in the tropics in another generation.
In the extremely long run, only sentient toolmaking life can defend the environment against geological and astronomical dangers. In another billion years, the oceans will have boiled off due to a warming sun. Without humanity to save it, life on Earth will be extinguished. And who will deflect the next asteroid to hit this planet if not us?
We have been hard on this planet for the last 50 or 100 years, and will be so for another 50 or 100, but in the long run, we are also the only stewards and protectors this planet and DNA based life has.

Interesting context. (title) I somewhat concur. You know me though, I gotta have a silly joke to go along with it all, but for now I shall spare us all the agony and just suggest we all learn chinese. Oops, just can't help myself.