This is true. My primary language is English, though I can speak Spanish if necessary. However, it takes a lot of extra brain power for me to do so, and that's why I prefer English. However, I have many cousins my age who don't understand or speak Spanish AT ALL. The whole Spanish as a primary language thing is strictly an immigrant issue, and not a "mainstream Hispanic" issue.
On the other hand, the fact that I did know Spanish probably accounted for anywhere from 200 to 300 of my extra SAT points, because Spanish is very close to Latin, and knowing Latin is VERY HELPFUL on the SAT test(the part where it helps to know the root of the word) and also later on in many college science courses (many scientific terms are based on Latin). So, I disagree with some FReepers who say, "No way is anyone forcing my kid taking a second language." But, I don't disagree from a cultural or philosophical standpoint; I disagree from an educational standpoint, because I myself was able to "use" my knowledge of Spanish (again, very close to Latin) in my college courses that had nothing to do with language.
However, for those who are college-bound and will need to do well on their SATs or perhaps are preparing for the scientific field, I would recommend Latin over Spanish. In my opinion, the next "hot" language to know in the business place AND at the CIA will be Chinese anyway (but the reason behind this is best saved for a whole other unrelated thread).
And so do I--strongly. I speak Russian, French and German, and took 1 semester of Spanish in college. I majored in linguistics/foreign languages, although my career ended up being in computer science.