Exactly Paco Dennis. You only have to consider how we would miss honey bees should they all disappear.
There is another reason - we are custodians of the land and of the creatures that have adapted to it. Australian fauna is very special, and if we Australians continue to destroy habitat we will lose so many unique species that we say we love.
the homeostasis of our planet is contingent on maintaining a vibrant and thriving biodiversity - ie: no pollinators = no food / no food = FAMINE!!! That we know of, there's no planet B. and if there is? how in the hell do we expatriate 800 billion people?
Things will be different in 10 or 20 million years, nature will likely have wiped all signs of human existence away. The Earth will still be young, and have several billions of years to host animal life, before the sun burns out.