That's not really true. They wanted to have a sense of worship, to have an experience of the Divine, and increasingly they looked to nature to take the place of the Church. They wanted nature to be their Church. It has its own integrity, reality, and history. Life lives off life in nature.
Animals have to eat each other.
There's a proliferation of life that leads to competition for scarce resources. When I look at nature, I see death more than I see life. Death is the necessity that makes life possible. But it's not. Nature does get out of balance, even without humans making things worse.