Why were the creoles and mestizos ready to fight for independence?

Every people who think they are oppressed are willing to fight for their cause. Usually they want independence, to separate from the "oppressors". Although their "national identity" is an imaginary concept, since they are mixed-race people, from white and indian background. They might think that they are in danger of extinction, since they are a minority, but really if the "oppressors" hadn't came there in the first place, those minorities wouldn't even exist. They have created themselves a mixed-race identity and think it needs an independent country, but why couldn't they live in a bigger state as a respected and respectful minority?