Scientific knowledge: De-extinction could offer insights into evolution and natural resources that are currently unavailable to us.
Technological advancement: De-extinction could be a big step forward for genetic engineering.
Environmental benefits: Threatened or damaged ecosystems could be restored with the help of certain now-extinct species.
Justice: If people pushed plant and animals species into extinction, perhaps we owe it to these species to try and bring them back.
Wonder: How cool would it be to see extinct species alive and kicking again?