I have lived in Australia since 1984, having come here from a non-english speaking country at the age of 13. I feel very Australian and am actually in the process of applying for Australian Citizenship so I can truly call myself Australian. I really don't associate myself much with my country of birth and am actually thinking of renouncing my citizenship there once I officially become Australian.
I don't hate my country of birth and the reason I want to renounce my citizenship is because I don't feel I should have to answer to them when I get married, divorced or have a child. I never go there and don't intend to live there again ever.
People who deny their nationality do so for many reasons, not necessarily because they're ashamed or have suffered discrimination. Often it has to do with reasons back in their country of birth.
Isn't it funny though that when people don't embrace their new country, they are told to 'go home if you don't like it' and yet when they do embrace it they are also judged and criticised.