I think they were talking about 'successful' expats. In other words - those who have moved here and succeeded and been happy. In our short few years here we reckon only about 1/10 that we've seen come here and to the mainland succeed to live here happily for the long term.
I didnt think you were Collyk, but wondered what the original article assumed. I think I would be pretty safe in saying that most of the ex pats in San Pedro do not define success the same way that most Americans do. I don't know about any other country's definition, but would imagine it's about the same.
It is exactly that different definition of success that I think attracts people here shuffles. Those who measure their success in more material or social status terms just can't hack it that most of us don't give a toodle who you are or how much money you have.