JH, I don't have an answer as to why, but my first four years in the cult was in a Spanish cong. and it was mostly women and a few white elders that spoke ok spanish.
When I've visited the congs. in Hawaii, I noticed the same thing, mostly women and imported white elders. Seems the ethnic men have very little interest in "reaching out" or even attending. I think in these cultures religious devotion seems to be the woman's job....