Conflict between man and the natural world is a common theme in literature—but not here! The speaker of "The Lake Isle of Innisfree" takes a totally harmonious, tree-hugging, green-loving approach to nature. He seems to think it's the cure for all that ails him. This poem has a lot to do with the speaker wanting to feel at home, or close to his roots. It's possible that he thinks he can get closer to his roots, or his true self, by abandoning the messy, hectic life of the city and embracing a life based on the simple and predictable patterns of nature.
The speaker neglects to consider the difficulties that going back to nature will entail. It's not all bees and flowers. It's tough out there.
The speaker doesn't necessarily love the country; he just wants to run away from his life in the city. He's welcoming any alternative at this point.