Art, if you lived in another country, would you give up your US citizenship to get citizenship there? Or would you like to retain the option to go back to your native land?
I can only speak for myself, and its not pride, but practicality that is keeping me from applying for US citizenship. I want to keep the option open to live anywhere I want or need to. Be it my native country, where my parents and friends still live, any number of countries who will allow citizens from my country to stay there, or here, where my wife and her family is.
Resident (legal) aliens who live in this country don't appreciate it less, and they give up considerable rights by not being citizens (like not being able to vote here and possibly in their home countries.)
All that said, if my native country would allow dual citizenship (as a lot of countries are doing now), I would apply for American citizenship in a heart beat.
P.S. thank your cousin for his sacrifice.