The people you mentioned are not only great, they almost created the IT industry. Their being American is just incidental. They would have been still great, if they were born in some other country.It is their deeds and not the country of origin that has made them great.
I have worked for Dr. A.P.J. Abdul Kalam.Niether me nor Dr. Kalam have ever worked for or in America.All the people you mentioned hold Dr. Kalam in high esteem specially Bill Gates.
I am very proud of being born,grown up, and worked in India, Otherwise I wouldn't have ever got a chance to work for the great man. Dr. Abdul Kalam
Conclusion. you don't need to be an American or be in America to work for great people.
Great people exist everywhere. U Thant, the most successful UN Secretary General hailed from a very small country Burma (Now Myanmar)+Vic Gundotra
Thinking needs to change at your end please.