Good question,
Well, I can speak for two ladies that I worked with, who were both from Puerto Rico. They chose to do the program because they studied here before and came back to study again while doing the program. they both like living in Madrid and saw the NALCA program as a way to come back to Spain.
I am also a minority in this setting as well.
It's not just Hispanics that are minorities in this program, but African-Americans as well. I am an African-American, 38 and am in the higher age range of Language Assistants. Language Assistants tend to be younger and fresh out of college with little teaching experience and many come to Spain because they like it and want t take advantage of living abroad.
So, in the end, your question wasn't weird at all.
Cheers,
Shawn