Steven, maybe Latinos don’t see the need to make the effort because they are so numerous. So they create a new Latino environment in California.
If you would migrate to Peru you would be a lonely Gringo and feel the need to speak the language of the authoctonous population.
.... I just forgot. American and British expat women who accompany their husbands to Europe where they work for big companies like Philip Morris or Procter and Gamble aren’t better than the Latinos migrants. They absolutely don’t learn a word of French and move around in closed social circles. They put their children in expensive private schools and rarely mingle with locals.