Gossip Girl and the Jews

Deborah Solomon interviews Josh Schwartz and asks my question about the show:

Why are the characters uniformly white, with old-money names like Blair Waldorf and Serena van der Woodsen that hark back to a time when high society was not integrated? Why are there no Jewish characters? It’s interesting, because on “The O.C.” I went out of my way to make those characters Jewish, not what you would expect to find in Orange County. But in New York, weirdly, I failed. I was working off of the source material.

Fair enough, but if accurate this just seems like a serious flaw in the source material. Asking for Jewish characters in a depiction of rich people in New York City isn't a plea for diversity for diversity's sake, it's just that New York day schools are full of Jews.