There are hundreds of thousands if not millions of Spanish speaking people and families living in LA, NYC, Miami etc. Many business in the area offer their services in Spanish, and there are enough entertainment options in Spanish that there isn't much of a need to learn English to get by day to day.
So first of all, the numbers on that page support my point without whinging over definitions.
But if you look at what I said, I didn't say anything about language spoken at home or primary language or anything like that, I explicitly said community of non-English speaking citizens, which pretty clearly means people that don't speak English anywhere.