In order to answer your question you need to understand Corsican, Italian, and French history. Until 1861, Italy was a series of independent republics. From the middle of the 15th centurty until 1768, Corsica was controlled by Genoa (actually, it was the property of the Bank of St. Giorgio!). Genoa exerted a very repressive government of Corsica and, as a result, there is no great love between Corsica and the Italians. As a matter of fact, during WWII, Italy tried to occupy Corsica unsuccessfully. In 1768, Genoa ceded Corsica to France in order to pay the debts it had with the Bank of St. Giorgio. When the French defeated the Corsican troops in 1769, for all intent and purposes Corsican resistance stopped. However, even today, most Corsicans favor a great deal of autonomy. If you visit Corsica you will see a resurgence of Corsican pride, music, art, literature, and language.
Corsica has a fascinating and tragic history. Read it!