Who are the Extinctionists?

The Extinctionists are a group who wipe out the last of an endangered species. Their policy is that if a creature has no positive and immediate use to human, then you should kill it. They believe useless animals have no right to use Earth's resources, grow fat, or live happily and comfortably if all humans can't enjoy these lifestyles.

What are some theories about extinction?

Various theories about extinction of species, human race, social classes, etc. Extinctionism (religious concept), about extinction of sinners in the afterlife Voluntary Human Extinction Movement (VHEMT), a movement for human extinction via antinatalism Extinctionists, a fictional radical group in Artemis Fowl (series), book 6

Could VHEMT be a human extinction movement?

Roots of VHEMT run as deep as human history. Potential for a voluntary human extinction movement has been around for as long as humans have. When Ice Age humans hunted animals to extinction, at least one of the sapient neanderthals among them may have reasoned beyond bewilderment.