Why did Romantic poets and 18th Century Poets write about nature?
Well, you should think over the Romantic theory, it says that SELF and NATURE were one, self-awareness was not a selfish dead end but a mode of knowledge opening up the universe. If one’s self were one with all humanity, then the individual had a moral duty to reform social inequalities and relieve human suffering. They were also fascinated by the sublimity of nature and its picturesque qualities. Hope it helps. Good question though.