I wholeheartedly disagree with that. Alexandria, maybe. But Fairfax County is pretty large: it encompasses Annandale, Springfield, and Centreville. Springfield has a heavy latino population, and Centreville and Annandale have like a 25% Asian population. Annandale even has a section called "Little Korea" for pete's sake.
To be fair, though, Alexandria is not fair from Arlington, and about the only people who can afford to live in either of them these days are trust fund babies.
I live in Alexandria and I can assure you that I am not a trust fund baby. Only child of a single parent with no college education, self-taught web developer with a decent income.
It is a diverse area. My neighborhood is single-family homes and I would wager half of them are just scraping by. Two blocks in either direction and you'll see abject poverty or McMansions nestled on too little land next to military housing from the 30s.
