As an aside - I'm confused why you care what language I choose to speak or teach my children? How does it hurt you for me to be multilingual? If you desire to see the world only through the prism of a single language, well, fair enough. Likewise you can feel free to eat the same food for every meal, listen to the same music endlessly, re-read the same authors, program in only one language, etc. Lots of us enjoy experiencing more of the great diversity of humanity.