Humans have learned to exploit nature for financial gain turning it deadly at times. A poppy is just a flower until its refined into heroin. Oil isn't bad for the environment until its drilled and pumped and used for fuel. Nothing is bad to start with until humans get a hold of it.
It's natural for predators to kill prey like tigers killing gazelles. I don't think any living thing wants to die but unfortunately it must happen in order for other animals, such as the tiger, to live. Wouldn't you want to live in a world where there was no need for killing, and there was no hunger, or suffrage of any kind. So to answer your question, not everything that is natural is by default a good.