There are over a billion speakers of Mandarin Chinese, but remember, almost all of them live in China or east Asia. Most of the ones living in the US speak English.
Whilst it's true that the majority of Chinese speakers outside China speak Cantonese, there remain many Mandarin-speaking communities across the world (including a substantial one here in Moscow). Most members of these communities - strange though it may seem - are monoglots, particularly as far as the older generation is concerned.

Maybe when the move to a country they should have enough consideration to learn the language.
What is the language? To pluck an example from the air, 45% of the population of South Florida have a native command of a language other than English. The USA, more than any other country on earth, is a linguistic melting-pot. You're richer for it.


Other than that, becides Spain, every spanish speaking country is either poor, or their infastructure is in bad need of repair. The only thing they can export is soccer players.
I'd hate to see philistinism take a hold of this forum. Are you seriously judging a language's value by the GDP of the countries in which it is spoken? Never wanted to read Neruda or Cervantes in the original? Utility ain't everything.