Why do we have three main races in malaysia?

chinese, malay and indian. please answer me. why do we have to be in three separate communities? I don't really mind about my malay heritage. to be honest, i feel more malaysian than being a malay and i don't really support malay supremacy. instead i prefer it to be malaysian supremacy. to other malays, chinese and indians in malaysia, would you give up your racial identity in favour national identity?fyi, i'm a secularist. I'm sorry if this question is somehow offensive to you but I just wanna know honest opinion from my countrymen/women. cheers