That is not entirely true. If you are referring to Futuro Aguila, those kids are Mexican who lived in the states because of hier parents. And they havent made the youth teams yet. the tryouts are not over
Not sure what kind of proof you want, but she's right. Getting back to the point about Americans in the MFL, I think it has a lot to do with the playing style. In general, northern European-style players have a hard time adapting to Latin-style soccer.
I think we will see some americans playing in the MFL in a few years. Chicago fire and Morelia signed a deal where they exchange players for training etc. This could be a way for a coach from the mfl to notice an american player (and since they are cheap). Not a superstar of the mfl like beasley but for example a guy like Kurtin of the fire. and of course the champions cup. When mls teams start beating mexican sides mfl coaches might consider looking into a good player an opposing mls side in a game had.
The Census measures (or tries to) all people who are living in the U.S., whether or not they are actually American citizens. If you are a foreigner living here, an immigrant, or with resident status, it makes perfect sense that you speak another language. Now, the statistic of those whose native language is English and have learned to speak another language fluently - Spanglish shouldn't count - might be more valid, but it's impossible to measure. And finally, I never said that no one in Mexico speaks English. I have no personal experience with that, mostly because when I go to Mexico, I don't speak English.
Prior to MLS there were a few Yanks that played in the MFL. Ramos, Balboa & Sorber come to mind. The greater language issues are that the players from the US don't speak Spanish and most Mexican teams aren't used to multilingual situations. As far as culture goes, Germany is less of a change for most US players and a very large US military presence helps as well. Because of the competitive situation, most Mexican teams are not going to bring in a Yank unless he's going to start. Where having a Mexican on a MLS team may put a few fans in the seats, having a Yank on a Mexican team isn't going to generate any income.