[If you are in a rush and /or don't want to read everything, I always tend to try to make a conclusion section in my answers to have the mains points (without the stories and explanation though), so if you want a quick answer, go see that section, otherwise enjoy the reading :) ]
I think to better answer your question, you need to see its relation to Corsica through his life. I’m going to try to do that, and I’m going to use a golden mine for Napoleon and Corsica, a website available in French and in English (https://www.napoleon.org/), I advise you to go on this website to find more (History but also so much source for more research).
Napoleon was born in Corsica (in 1769) and left the island a little before he was 10 years old, he left to study in France. Corsica was already a part of France, but like a lot of islands in the Mediterranean they had some autonomy. At that time (and some could argue it’s still the case today), people coming from other part of France were bullied, isolated and sometimes considered as misfits. He knows at that time and claim his Corsican heritage, you could tell that this relocation is the root of his destiny and his link to Corsica that will influence his work. Being “taken away” from his home-land so young, he gets his knowledge of Corsica only through what he can read and have an idealistic idea of Corsica as a perfect political system with a pacific society. He develops a hate against the Continental French (which I will refer to the French for simplicity), probably due to the bullying he suffered during his youth. He will even qualify the French of “people with very different and foreign manners,” of “monsters,” and “enemies of the liberty” in his different books (“Sur la Corse,” “Napoleon Inconnu”). In his book “Sur l’histoire de la Corse” he even swears to never forgive the French” whom are just using their monarchy to overrule the island and that the “French are just tyrants.”
It's important to note that this behavior is very “typical” to the Corsican, with an island, they are cut-off from the rest of the world and tend to develop a defiant attitude toward foreigners. They are people very patriotic, with honor, that uses violence, banditry, believe in freedom, suffer a lot, are heroic with a sense of justice, and a sense of self affirmation individualistic and collectively speaking (all of this is a stereotype and a trend in qualification, it is not meant to be neither complimentary nor critical toward the Corsicans people).
Napoleon in his acts and temper is the perfect example of a Corsican. He speaks and behave like a true Corsican. For a long time, Napoleon admire Paoli, whom was a strong Corsican separatist, and it’s even reported by Napoleon himself that he admired Jean-Jacques Rousseau. Jean-Jacques Rousseau is sometimes considered as the father of the ideology of “self-determination of the people on their land” (in other words : he was a federalist, regionalist). From the data gathered through Napoleon’s books, his fervent admiration for Paoli is reported to last until 1791 before a big schism happened within the Corsican society.
Napoleon comes back in Corsica in September 1789 during the Revolution and notices that the Corsican people do not follow the Revolution nor they care about it, it’s like Corsica is out-of-time, frozen in a moment. That even is determining for Napoleon, it’s the moment where he choses to act, to move its people, to guide them toward a brighter future.
He starts then to spread the idea of the Revolution in Corsica, he creates clubs (in this context understand group of people gathered around an idea, here around the ideology of the Revolution), he even creates a National Garde. His actions are reprimanded but those reprimands don’t have a real effect, on the contrary, the idea of self-affirmation as a person and as a community is even favorable to the spread of Napoleon’s work. At first during this movement, it’s reported than Napoleon is still for a full Independence of the Island of Corsica, but that will change later on. His actions are also a proof of his “genie” because he even refuses to be too violent in his actions to avoid a Corsican Civil War between the Royalist Corsicans and the Patriotic Corsicans. His first political document is made in Corsica (in October 1789, where he questions the legitimacy of the Corsican deputies), another proof of his attachment to Corsica. Following that, he manages to get that Corsica will be rule in the same way as the Continent, under the same Constitution.
That marks the beginning of the divergence between Napoleon and Paoli ; Napoleon doesn’t want the Independence of the Island like Paoli, but he wants a more federalist France where Corsica will still be a part of France but will be rule by Corsican, that Corsica will remain somewhat autonomous.
The years between 1791 and 1793 are a real important moment for Napoleon, it’s the moment where he acquires a more methodic method to analyze, a move away from his idyllical idea of Corsica. He remains very proud of his origins but start to blame the problem of Corsica on its History where the Island has been suffering from vile enemies all the times (the French, Genoa, the Sarasin…). The Corsican people are not the problem, it’s the people who invaded Corsica whom turned the Corsican into violent people that “taught to arm the son against his father, the nephew against his uncle, the brother against his brother.”
Napoleon after all his success, turns more into a Republican which would conflict with his initial ideas of a very autonomous Corsica. He starts to turn his back on his Island due to a promising future, because he feels inspired by a brighter future on the Continent, where he could fulfil his desires and wishes of a better world. This change however makes him a foreigner in his own land, even if he remains Corsican in his passion, he becomes a target of attacks and obvious defiance in Corsica.
He ends up disgust by Corsica, he will never deny his origins and no matter what people say, he knew that his Corsican heritage and behavior were the ones that brought him as Emperor of France.
In conclusion :
- Napoleon left Corsica very young, and being pushed around due to his origins, he developed a strong patriotism and love for Corsica.
- During his teenage years, he starts to realize that Corsica is not an idyllic land as he pictured younger.
- He remains very autonomous, and federalist toward Corsica until his successes in Corsica where he starts to made up a more realistic idea of the Island and “its possible place within France.”
- Then, he ends up by turning his back on the Island because of his career and position. He will always thank Corsica for what it brought to and in him, he will keep a respect toward its Island.